PHP 7.0.6 Released

is_numeric

(PHP 4, PHP 5, PHP 7)

is_numeric Finds whether a variable is a number or a numeric string

Description

bool is_numeric ( mixed $var )

Finds whether the given variable is numeric. Numeric strings consist of optional sign, any number of digits, optional decimal part and optional exponential part. Thus +0123.45e6 is a valid numeric value. Hexadecimal (e.g. 0xf4c3b00c), Binary (e.g. 0b10100111001), Octal (e.g. 0777) notation is not allowed.

Parameters

var

The variable being evaluated.

Return Values

Returns TRUE if var is a number or a numeric string, FALSE otherwise.

Examples

Example #1 is_numeric() examples

<?php
$tests 
= array(
    
"42",
    
1337,
    
0x539,
    
02471,
    
0b10100111001,
    
1337e0,
    
"not numeric",
    array(),
    
9.1
);

foreach (
$tests as $element) {
    if (
is_numeric($element)) {
        echo 
"'{$element}' is numeric"PHP_EOL;
    } else {
        echo 
"'{$element}' is NOT numeric"PHP_EOL;
    }
}
?>

The above example will output:

'42' is numeric
'1337' is numeric
'1337' is numeric
'1337' is numeric
'1337' is numeric
'1337' is numeric
'not numeric' is NOT numeric
'Array' is NOT numeric
'9.1' is numeric

Changelog

Version Description
7.0.0 Strings in hexadecimal (e.g. 0xf4c3b00c) notation are no longer regarded as numeric strings, i.e. is_numeric() returns FALSE now.

See Also

  • ctype_digit() - Check for numeric character(s)
  • is_bool() - Finds out whether a variable is a boolean
  • is_null() - Finds whether a variable is NULL
  • is_float() - Finds whether the type of a variable is float
  • is_int() - Find whether the type of a variable is integer
  • is_string() - Find whether the type of a variable is string
  • is_object() - Finds whether a variable is an object
  • is_array() - Finds whether a variable is an array

User Contributed Notes

dave dot marr at gmail dot com
4 years ago
If you want the numerical value of a string, this will return a float or int value:

<?php
function get_numeric($val) {
  if (
is_numeric($val)) {
    return
$val + 0;
  }
  return
0;
}
?>

Example:
<?php
get_numeric
('3'); // int(3)
get_numeric('1.2'); // float(1.2)
get_numeric('3.0'); // float(3)
?>
sobolanx at gmail dot com
5 years ago
Note that the function accepts extremely big numbers and correctly evaluates them.

For example:

<?php
    $v
= is_numeric ('58635272821786587286382824657568871098287278276543219876543') ? true : false;
   
   
var_dump ($v);
?>

The above script will output:

bool(true)

So this function is not intimidated by super-big numbers. I hope this helps someone.

PS: Also note that if you write is_numeric (45thg), this will generate a parse error (since the parameter is not enclosed between apostrophes or double quotes). Keep this in mind when you use this function.
Stephen
9 years ago
The documentation is not completely precise here. is_numeric will also return true if the number begins with a decimal point  and/or a space, provided a number follows (rather than a letter or punctuation). So, it doesn't necessarily have to start with a digit.
Martyn Ranyard
5 years ago
The documentation does not clarify what happens if you the input is an empty string - it correctly returns false in my experience.  Useful to state these odd cases, for when you see code that checks for an empty string and is_numeric, you can tell it's a waste of a comparison.
stew_wilde at hotmail dot com
12 years ago
When using the exec() function in php to execute anther php script, any command line arguments passed the script will lose their type association, regardless of whether they are numeric or not, the same seems to hold true for strings as well.

ie : two scripts test.php:

<?php
$val
= trim($argv[1]);
echo
is_string($val);
?>

and testwrapper.php:

<?php
$tmp
= 5;
exec("php ./test.php ".$tmp);
?>

Executing testwrapper.php on the command line will echo nothing (ie false), and false will be returned regardless of any escaping of parameters or other such attempts to overcome this.  The solution then is to explicitly cast $val in test.php to be an int and then is_numeric will work.  But as stated the same test was performed using a string for $val and the is_string() function and the same thing occurs.  Not the end of the world, but something to be aware of :)
moskalyuk at gmail dot com
9 years ago
is_numeric fails on the hex values greater than LONG_MAX, so having a large hex value parsed through is_numeric would result in FALSE being returned even though the value is a valid hex number
andrea dot vacondio at gmail dot com
10 years ago
Two simple functions using is_numeric:

<?php

function is_odd($num){
     return (
is_numeric($num)&($num&1));
}

function
is_even($num){
     return (
is_numeric($num)&(!($num&1)));
}

//examples
echo "1: odd? ".(is_odd(1)? "TRUE": "FALSE")."<br />";
//is_numeric(0) returns true
echo "0: odd? ".(is_odd(0)? "TRUE": "FALSE")."<br />";
echo
"6: odd? ".(is_odd(6)? "TRUE": "FALSE")."<br />";
echo
"\"italy\": odd? ".(is_odd("italy")? "TRUE": "FALSE")."<br />";
echo
"null: odd? ".(is_odd(null)? "TRUE": "FALSE")."<br /><br />";
echo
"1: even? ".(is_even(1)? "TRUE": "FALSE")."<br />"
echo
"0: even? ".(is_even(0)? "TRUE": "FALSE")."<br />";
echo
"6: even? ".(is_even(6)? "TRUE": "FALSE")."<br />";
echo
"\"italy\": even? ".(is_even("italy")? "TRUE": "FALSE")."<br />"
echo
"null: even? ".(is_even(null)? "TRUE": "FALSE")."<br />";

?>
And here is the result:
1: odd? TRUE
0: odd? FALSE
6: odd? FALSE
"italy": odd? FALSE
null: odd? FALSE

1: even? FALSE
0: even? TRUE
6: even? TRUE
"italy": even? FALSE
null: even? FALSE
namik at hub-cafe dot net
10 years ago
I needed a number_suffix function that takes numbers with thousand seperators (using number_format() function).  Note that this doesn't properly handle decimals.

Example:
<?= number_suffix('1,021') ?> returns: 1,021st

Also, increasing the range above the condition statements increases efficiency.  That's almost 20% of the numbers between 0 and 100 that get to end early.

<?
  function number_suffix($number)
  {
    // Validate and translate our input
    if ( is_numeric($number) )
    {
      // Get the last two digits (only once)
      $n = $number % 100;
    } else {
     // If the last two characters are numbers
     if ( preg_match( '/[0-9]?[0-9]$/', $number, $matches ) )
     {
       // Return the last one or two digits
       $n = array_pop($matches);
     } else {
       // Return the string, we can add a suffix to it
       return $number;
     }
    }
    // Skip the switch for as many numbers as possible.
    if ( $n > 3 && $n < 21 )
      return $number . 'th';

    // Determine the suffix for numbers ending in 1, 2 or 3, otherwise add a 'th'
    switch ( $n % 10 )
    {
      case '1': return $number . 'st';
      case '2': return $number . 'nd';
      case '3': return $number . 'rd';
      default:  return $number . 'th';
    }
  }
?>
rontarrant at NO_SPAMsympatico dot ca
9 years ago
Here's an even simpler pair of functions for finding out if a number is odd or even:

function IS_ODD($number) { return($number & 1); }

function IS_EVEN($number) { return(!($number & 1)); }

Test:
$myNumber = 151;

if(IS_ODD($myNumber))
    echo("number is odd\n");
else
    echo("number is NOT odd\n");

if(IS_even($myNumber))
    echo("number is even\n");
else
    echo("number is NOT even\n");

Results:
number is odd
number is NOT even
sebu
10 years ago
Referring to previous post "Be aware if you use is_numeric() or is_float() after using set_locale(LC_ALL,'lang') or set_locale(LC_NUMERIC,'lang')":

This is totally wrong!

This was the example code:

-----
  set_locale(LC_NUMERIC,'fr');
  is_numeric(12.25); // Return False
  is_numeric(12,25); // Return True
  is_float(12.25); //Return False
  is_float(12,25); //Return True
-----

This is nonsense!

- set_locale() does not exist, you must use setlocale() instead
- you have to enclose 12,25 with quotes; otherwise PHP will think that
the function gets _two_ arguments: 12 and 25 (depending on PHP version and setup you may additionally get a PHP warning)
- if you don't enclose 12,25 with quotes the first argument will be the inspected value (12), the second value (25) is discarded. And is_numeric(12) and is_float(12) is always TRUE

Corrected Example:

----
  setlocale(LC_NUMERIC,'fr');
  is_numeric(12.25); // Return True
  is_numeric("12,25"); // Return False
  is_float(12.25); //Return True
  is_float("12,25"); //Return False
----

Remarks:
- is_float(12.25) is _always_ TRUE, 12.25 is a PHP language construct (a "value") and the way PHP interpretes files is definitely _not_ affected by the locale
- is_float("12,25") is _always_ FALSE, since is_float (other than is_numeric): if the argument is a string then is_float() always returns FALSE since it does a strict check for floats

And the corrected example shows: you get the _same_ results for every possible locale, is_numeric() does not depend on the locale.
jamespam at hotmail dot com
10 years ago
Here's a function to determine if a variable represents a whole number:

function is_whole_number($var){
  return (is_numeric($var)&&(intval($var)==floatval($var)));
}

just simple stuff...
is_whole_number(2.00000000001); will return false
is_whole_number(2.00000000000); will return true
andi_nrw at hotmail dot com
13 years ago
<?php
/* This function is not useful if you want
to check that someone has filled in only
numbers into a form because for example
4e4 and 444 are both "numeric".

I used a regular expression for this problem
and it works pretty good. Maybe it is a good
idea to write a function and then to use it.

$input_number = "444"; // Answer 1
$input_number = "44 "; // Answer 2
$input_number = "4 4"; // Answer 2
$input_number = "4e4"; // Answer 2
$input_number = "e44"; // Answer 2
$input_number = "e4e"; // Answer 2
$input_number = "abc"; // Answer 2
*/
$input_number = "444";

if (
preg_match ("/^([0-9]+)$/", $input_number)) {
     print
"Answer 1";
} else {
     print
"Answer 2";
}
?>
mdallaire at virtuelcom dot com
11 years ago
Sometimes, we need to have no letters in the number and is_numeric does not quit the job.
You can try it this ways to make sure of the number format:

    function new_is_unsigned_float($val) {
        $val=str_replace(" ","",trim($val));
        return eregi("^([0-9])+([\.|,]([0-9])*)?$",$val);
    }

    function new_is_unsigned_integer($val) {
        $val=str_replace(" ","",trim($val));
        return eregi("^([0-9])+$",$val);
    }

    function new_is_signed_float($val) {
        $val=str_replace(" ","",trim($val));
        return eregi("^-?([0-9])+([\.|,]([0-9])*)?$",$val);
    }

    function new_is_signed_integer($val) {
        $val=str_replace(" ","",trim($val));
        return eregi("^-?([0-9])+$",$val);
    }

It returns 1 if okay and returns nothing "" if it's bad number formating.
eagleflyer2 at lycos dot com
13 years ago
Hi !
Many of you may have experienced that the 'is_numeric' function seems to fail always when form entries are checked against their variable type. So the function seems to return  'false' even if the form entry was aparently a number or numeric string.

The solution is pretty simple and no subroutines or fancy operations are necessary to make the 'is_numeric' function usable for form entry checks:

Simply strip off all (invisible) characters that may be sent along with the value when submitting a form entry.

Just use the 'trim' function before 'is_numeric'.

Example:

$variable = trim($variable);
if (is_numeric($variable)
{...#do something#...}
else
{...#do something else#...}
Elwin van Huissteden
9 years ago
To James holwell:

Maybe your function was more strickt, but profides FALSE to any numeric string that wasnt written in the English/American notition. To enable a person to use the both the English/American and the rest of the world's way:

<?php
 
function my_is_numeric($value)
  {
   return (
preg_match ("/\A(-){0, 1}([0-9]+)((,|.)[0-9]{3, 3})*((,|.)[0-9]){0, 1}([0-9]*)\z/" ,$value) == 1);
  }
?>

Other than that, i'd recommend using yours, if it works (i havent tested either yours or mine)
By using mine, there might be a slight chance to not being able to do calculations with the numeric string if it's not the English/American way.

(*Note:
-the E/A way of writing 1 million (with decimal for 1/50): 1,000,000.02
-the global way of writing 1 million (with decimal for 1/50): 1.000.000,02
kouber at saparev dot com
12 years ago
Note that this function is not appropriate to check if "is_numeric" for very long strings. In fact, everything passed to this function is converted to long and then to a double. Anything greater than approximately 1.8e308 is too large for a double, so it becomes infinity, i.e. FALSE. What that means is that, for each string with more than 308 characters, is_numeric() will return FALSE, even if all chars are digits.

However, this behaviour is platform-specific.

http://www.php.net/manual/en/language.types.float.php

In such a case, it is suitable to use regular expressions:

function is_numeric_big($s=0) {
  return preg_match('/^-?\d+$/', $s);
}
renimar no spam at nospam yahoo dot com
11 years ago
A little function to ordinalize numbers using is_numeric() and accounting for the numbers in the teens.

<?php
function ordinalize($num) {

        if (!
is_numeric($num))
                return
$num;

        if (
$num >= 11 and $num <= 19)
                return
$num."th";
        elseif (
$num % 10 == 1 )
                return
$num."st";
        elseif (
$num % 10 == 2 )
                return
$num."nd";
        elseif (
$num % 10 == 3 )
                return
$num."rd";
        else
                return
$num."th";

}

// Demo
for ($i=1; $i<=25; $i++) {
        print
ordinalize($i) . " ";
}

// The loop returns:
// 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th
// 13th 14th 15th 16th 17th 18th 19th 20th 21st 22nd
// 23rd 24th 25th

?>
jeffvanhees at gmail dot com
3 years ago
Function for checking all the values in an array for being numeric:

<?php
function is_numeric_array($array) {
    foreach (
$array as $key => $value) {
        if (!
is_numeric($value)) return false;
    }
    return
true;
}

$array_not_numeric = array('1', '2', 3, 'a'); // returns false
$array_numeric = array('1', '2', 3, 4); // returns true
?>
Kiam
6 years ago
empty(trim($test, '+-.,0123456789')) doesn't assure you $test contains a number. It returns TRUE also for a string containing ".+1234.56", which is not a valid number.
jsnell at e-normous dot com
3 years ago
Note that this function handles leading spaces differently than is_int(), is_float(), is_real(), is_long(), and is_double().

is_numeric(" 12345") = true
is_int(" 12345") = false
is_float(" 12345") = false
is_real(" 12345") = false
is_long(" 12345") = false
is_double(" 12345") = false
blazatek at wp dot pl
12 years ago
the best way to check whether
variable is numeric is to check its ascii code :)

function is_num($var)
{
    for ($i=0;$i<strlen($var);$i++)
    {
        $ascii_code=ord($var[$i]);
       
        if ($ascii_code >=49 && $asci_code <=57)
            continue;
        else
            return false;
    }
   
        return true;
}
this function can be usefull if you wont to chec eg $_POST

function test_post($tab)
{
       
        $post = array();
        $post=$tab;
        echo $tab["user_name"];
        foreach ($post as $varname => $varvalue)
        {
        if (empty($varvalue))
        {
            $post[$varname] = null;
      
        }elseif (is_num($varvalue))
        {
                        $post[$varname]=trim($varvalue);
    $post[$varname]=strip_tags($varvalue);   
    $post[$varname]=intval($varvalue);
    $post[$varname]=addslashes($varvalue);   
    }else
    {   
                  $post[$varname]=NULL;
    }
            }
        }//forech    
    return $post;
}
Nitrogen
5 years ago
I find it a little weird that people are having issues with ordinal numbers, it's pretty easy..
Notes are in the commenting, check out the example outputs.

<?php

function ordinal($i='') {
 
// a temporary value we can change, and keep the original value.
 
$o=$i;

 
// suffixes = 0th, 1st, 2nd, third == zeroth, first, second, third
 
$s=array('th','st','nd','rd');

 
// if input just so happens to be a string, we check to make sure it
  // still holds a numeric value and only acquire the last 2 numbers.
  // if it's not a string, nor an integer, we freak out and say no.
 
if(!is_int($o))
    if(
ctype_digit($o))
     
$o=(int)substr($o,-2,2);
    else
      return(
false);

 
// basically, if $o is between 11 and 19, we use 'th'
  // otherwise we use the last digit and if it's over
  // 4 then we use 0 (for the $s array index).
 
return($i.$s[($o%100>10&&$o%100<20)?0:($o%10<4?$o%10:0)]);
}

var_dump(ordinal(5));

/* Example Outputs of ordinal():
  0th, 1st, 2nd, 3rd, 4th, ..., 9th,
  10th, 11th, 12th, 13th, 14th, ..., 19th,
  110th, 111th, ..., 199th, 200th, 201st.

  ordinal('-1'); returns false because ctype_digit hates anything that
  isn't strictly 0 through 9 and '-' trips it to false.

  ordinal('asdf'); returns false for the exact same reason.

  ordinal(); returns false because it's blank.

  signed integers on a 32-bit system (and the same issue on a 64-bit
  system using 0x7FFFFFFFFFFFFFFF because of two's compliment,
  anything higher will become a negative number):
  ordinal(0x7FFFFFFF  ); returns 2147483647th (which is correct)
  ordinal(0x7FFFFFFF+1); returns false.
*/

?>
james.holwell( at )exeter.ox.ac.uk
9 years ago
In reply to www.kigoobe.com, a more strict expression is

<?php
 
function my_is_numeric($value)
  {
    return (
preg_match ("/^(-){0,1}([0-9]+)(,[0-9][0-9][0-9])*([.][0-9]){0,1}([0-9]*)$/", $value) == 1);
  }
?>

This will not match strings like -6,77.8,8 which are matched by the below expression, and instead requires a single decimal point, with at least one character following, and only permits comma-separation when the right hand side is a triplet.
codeslinger at compsalot dot com
6 years ago
if speed is important, the liberal use of regex should be avoided, especially complex ones like those here.

For most purposes, this will be sufficient and has the advantages of both speed and clarity.

$BoolResult = empty(trim($Test, '+-.,0123456789'));

If the $Test contains any character that is not a valid part of a number the remaining string will not be empty.

if you want to be more restrictive of the '+-'  then you can use a separate trim for that and nest it.  Keep in mind that some notations pt the sign to the right of the number instead of to the left.  Depending upon your specific application you can also choose to ignore spaces and allow for 'e' notation.

I also use this approach when testing for other character sets such as Hex.
ben at chico dot com
2 years ago
Apparently NAN (Not A Number) is a number for the sake of is_numeric().

<?php
echo "is ";
if (!
is_numeric(NAN))
echo
"not ";
echo
"a number";
?>

Outputs "is a number". So something that is NOT a number (by defintion) is a number...
Joris Berthelot
2 years ago
There's no way to check if a string contains a float number so here's a tricky one:

<?php
function isFloat($input)
{
    return
is_numeric(preg_replace('/[^-0-9\.]/', null, $input));
}
ja at krystof dot org
9 years ago
Here is a simple function to recognize whether the value is a natural number: (Zero is often exclude from the natural numbers, that's why there's the second parameter.)

<?php
function is_natural($val, $acceptzero = false) {
$return = ((string)$val === (string)(int)$val);
if (
$acceptzero)
 
$base = 0;
else
 
$base = 1;
if (
$return && intval($val) < $base)
 
$return = false;
return
$return;
}
?>
joe at kewlmail dot net
12 years ago
Here is a simple function that I found usefull for filtering user input into numbers. Basically, it attempts to fix fat fingering. For example:

$userString = "$654.4r5";

function numpass_filter($userString){ 
    $money = explode(".", $userString);
    //now $money[0] = "$645" and $money[1] = "4r5"

    //next remove all characters save 0 though 9
    //in both elements of the array
    $dollars = eregi_replace("[^0-9]", null, $money[0]);
    $cents = eregi_replace("[^0-9]", null, $money[1]);

    //if there was a decimal in the original string, put it back
    if((string)$cents!=null){
        $cents = "." . $cents;
    }

   $result = $dollars . $cents;

    return($result);
}

The output in this case would be '654.45'.
Please note that this function will work properly unless the user fat fingers an extra decimal in the wrong place.
Tim Robert-Fitzgerald
10 months ago
Be careful when using `is_numeric()` to validate user input and protect against SQL injection. According to wiki.hashphp.org,

"Many people reach for is_numeric() thinking this is a good approach, and it will seem to work just fine. However the problem with is_numeric() isn't that it can't detect an integer, it is that it detects a lot more than just integers. All of the following are valid numbers to is_numeric():

- 1
- 1.123
- 0xFF
- +0123.45e6

See the problem? If we really want just an integer, this function is too broad."

Source: http://wiki.hashphp.org/Validation#Why_is_numeric.28.29_is_bad
root at pspider dot com
2 days ago
Hey everyone! I have brought a handy function which checks if the input is an IP address. I posted here because it is a numeric string, and uses function is_numeric();

<?php
/*
    is_ipaddress($input)   
*/
function is_ipaddress($input) {   
   
$ctra = 0;       
   
$tmpout = explode(".",$input);   
    if (
count($tmpout) == 4) {
           
// There are four sections in the array (Ex. XXX.XXX.XXX.XXX)
            // Check if all elements of array are a number (Ex. 127.0.0.1)
           
foreach ($element in $tmpout) {   
                if (
is_numeric($element)) {
                       
// The element is numeric.
                       
++$ctra;                   
                }                       
            }           
           
// Is the count of numeric elements = 4 ?
           
if ($ctra == 4) {   
                return
true;               
            }
            else {
                return
false;               
            }   
    }
    else {   
        return
false;       
    }   
}
?>

If you can condense this further, please let me know @ my email address I have posted under. Thanks!

nJoy~!!!
Vasiliy Makogon
23 days ago
If you want detect integer of float values, which presents as pure int or float, and presents as string values, use this functions:

<?php
function isInteger($val)
{
    if (!
is_scalar($val) || is_bool($val)) {
        return
false;
    }
    if (
is_float($val + 0) && ($val + 0) > PHP_INT_MAX) {
        return
false;
    }
    return
is_float($val) ? false : preg_match('~^((?:\+|-)?[0-9]+)$~', $val);
}

function
isFloat($val)
{
    if (!
is_scalar($val)) {
        return
false;
    }
    return
is_float($val + 0);
}

foreach ([
   
'11111111111111111', 11111111111111111, // > PHP_INT_MAX - presents in PHP as float
   
1, '10', '+1', '1.1', 1.1, .2, 2., '.2', '2.',
   
'-2.', '-.2', null, [], true, false, 'string'
] as $value) {
    echo
$value . ':' . gettype($value) . ' is Integer? - '  . (isInteger($value) ? 'yes' : 'no') . PHP_EOL;
    echo
$value . ':' . gettype($value) . ' is Float? - '  . (isFloat($value) ? 'yes' : 'no') . PHP_EOL;
}
?>

Output:

11111111111111111:string is Integer? - no
11111111111111111:string is Float? - yes
1,1111111111111E+16:double is Integer? - no
1,1111111111111E+16:double is Float? - yes
1:integer is Integer? - yes
1:integer is Float? - no
10:string is Integer? - yes
10:string is Float? - no
+1:string is Integer? - yes
+1:string is Float? - no
1.1:string is Integer? - no
1.1:string is Float? - yes
1,1:double is Integer? - no
1,1:double is Float? - yes
0,2:double is Integer? - no
0,2:double is Float? - yes
2:double is Integer? - no
2:double is Float? - yes
.2:string is Integer? - no
.2:string is Float? - yes
2.:string is Integer? - no
2.:string is Float? - yes
-2.:string is Integer? - no
-2.:string is Float? - yes
-.2:string is Integer? - no
-.2:string is Float? - yes
:NULL is Integer? - no
:NULL is Float? - no
Array:array is Integer? - no
Array:array is Float? - no
1:boolean is Integer? - no
1:boolean is Float? - no
:boolean is Integer? - no
:boolean is Float? - no
string:string is Integer? - no
string:string is Float? - no
lihatskiym at gmail dot com
7 months ago
Check that value is whole numeric or is whole integer.
<?php
function whole_numeric($val)
{
    if (
is_numeric($val)
        &&
floor($val) == $val)
    {
        if ((string)
$val === (string)0)
            return
true;
        elseif(
ltrim((string)$val, '0') === (string)$val)
            return
true;
    }

    return
false;
}

function
whole_int($val)
{
   
$val = strval($val);
   
$val = str_replace('-', '', $val);

    if (
ctype_digit($val))
    {
        if (
$val === (string)0)
            return
true;
        elseif(
ltrim($val, '0') === $val)
            return
true;
    }

    return
false;
}
?>

Result will be like this:

<?php
whole_numeric
('-1.0');  // true
whole_numeric(0);        // true
whole_numeric('0');      // true
whole_numeric('00');     // false
whole_numeric(1);        // true
whole_numeric('1');      // true
whole_numeric('1.0');    // true
whole_numeric('1,0');    // false
whole_numeric('1.2');    // false
whole_numeric('001');    // false
whole_numeric(array()); // false

whole_int('-1.0');    // false
whole_int('-1');       // true
whole_int(0);          // true
whole_int('0');        // true
whole_int('00');      // false
whole_int(1);          // true
whole_int('1');         // true
whole_int('1.0');      // false
whole_int('1.2');      // false
whole_int('001');     // false
whole_int(array()); // false
?>
vikramverma214 at gmail dot com
4 months ago
check if given string is mobile number

function filterNumber($str)
        {
            //remove non number
            $count = strlen($str);
            $newNumber = "";
            for($i = 0; $i<$count; $i++)
            {
                if(is_numeric($str[$i]))
                    $newNumber .= $str[$i];
            }

            //removes leading 0s
            $newNumber = ltrim($newNumber, '0');

            //remove 91 in starting, 91 is specific to Indian Numbers
            if(strlen($newNumber) == 12)
            {
                if(substr($newNumber, 0, 2) == '91')
                    $newNumber = substr($newNumber, 2);
            }

            //final check for length 10
            if(strlen($newNumber) != 10 )
                return null;
            else
                return $newNumber;
        }
charlike dot mike at mail dot bg
2 years ago
I think that is best check solution if u want to create real calculator for example :)

<?php
function is_number($var)
{
    if (
$var == (string) (float) $var) {
        return (bool)
is_numeric($var);
    }
    if (
$var >= 0 && is_string($var) && !is_float($var)) {
        return (bool)
ctype_digit($var);
    }
    return (bool)
is_numeric($var);
}

is_number(12); // true
is_number(-12); // true
is_number(-12.2); // true
is_number("12"); // true
is_number("-124.3"); // true
is_number(0.8); // true
is_number("0.8"); // true
is_number(0); // true
is_number("0"); // true
is_number(NULL); // false
is_number(true); // false
is_number(false); // false
is_number("324jdas32"); // false
is_number("123-"); // false
is_number(1e7); // true
is_number("1e7"); // true
is_number(0x155); // true
is_number("0x155"); // false
?>
Magnus Deininger, dma05 at web dot de
7 years ago
regarding the global vs. american numeral notations, it should be noted that at least in japanese, numbers aren't grouped with an extra symbol every three digits, but rather every four digits (for example 1,0000 instead of 10.000). also nadim's regexen are slightly suboptimal at one point having an unescaped '.' operator, and the whole thing could easily be combined into a single regex (speed and all).

adjustments:

<?php
$eng_or_world
= preg_match
 
('/^[+-]?'. // start marker and sign prefix
 
'(((([0-9]+)|([0-9]{1,4}(,[0-9]{3,4})+)))?(\\.[0-9])?([0-9]*)|'. // american
 
'((([0-9]+)|([0-9]{1,4}(\\.[0-9]{3,4})+)))?(,[0-9])?([0-9]*))'. // world
 
'(e[0-9]+)?'. // exponent
 
'$/', // end marker
 
$str) == 1;
?>

i'm sure this still isn't optimal, but it should also cover japanese-style numerals and it fixed a couple of other issues with the other regexen. it also allows for an exponent suffix, the pre-decimal digits are optional and it enforces using either grouped or ungrouped integer parts. should be easier to trim to your liking too.
jbezorg at gmail dot com
7 years ago
"$e = (int) substr( $n , -2 );"

What the heck am I thinking.

<?php
function number_suffix2($n)
{
   
$s = array( 1->'st' , 2=>'nd' , 3=>'rd' );
   
$e = $n % 100;
   
$x = $n % 10;
  
    return
$n.( ( $x > 0 && $x < 4 && ( $e < 11 || $e > 13 ) ) ? $s[$x] : 'th' );
}
?>
kendsnyder at gmail dot com
8 years ago
Be careful when using is_numeric() to escape SQL strings.  is_numeric('0123') returns true but 0123 without quotes cannot be inserted into SQL.  PHP interprets 0123 without quotes as a literal octal number; but SQL just throws a syntax error.

<?php
is_numeric
('0123'); // true
is_numeric(0.123); // true
is_numeric('0.123'); // true
is_numeric(123); // true
is_numeric('123'); // true
is_numeric('foo'); // false
?>

Casting a value to float then string and comparing it to the original value cast as string as the same effect as is_numeric but returns false for numeric strings that begin with zero and have no decimal point.  Examples:
<?php
function isDecimalNumber($n) {
  return (string)(float)
$n === (string)$n;
}

isDecimalNumber('0123'); // false
isDecimalNumber(0.123); // true
isDecimalNumber('0.123'); // true
isDecimalNumber(123); // true
isDecimalNumber('123'); // true
isDecimalNumber('foo'); // true

?>
akam at akameng dor com
4 years ago
<?php
$d
= @$_GET['d'];

/*
assuming that passing value of d in the mysql
$sql = "select * from books where bookid = '$d' "
*/

/*
now check if $d is numeric?
*/

if(!is_numeric($d)){
$d = preg_replace("/[^0-9]+/", "", $d);
}
echo
"Cleared value: $d \n<br />Original Vlaue:".@$_GET['d'];
//then using clear value of $d in the mysql query
$sql = "select * from books where bookid = '$d' ";
?>
Example:
?d=52;d;s;s'2233l'[[22

Outpt:

Cleared value: 52223322
Original Vlaue:52;d;s;s'2233l'[[22
mariusads::at::helpedia.com
9 years ago
Test if a number is positive and contains only 0-9:

function is_number($number)
{
    $text = (string)$number;
    $textlen = strlen($text);
    if ($textlen==0) return 0;
    for ($i=0;$i < $textlen;$i++)
    { $ch = ord($text{$i});
       if (($ch<48) || ($ch>57)) return 0;
    }
    return 1;
}

returns

0 : number contain character outside 0-9
1 : valid number.
Titouthat
11 years ago
This function converts an input string into bool, int or float depending on its content.

<?php
function convert_type( $var )
{
    if(
is_numeric( $var ) )
    {
        if( (float)
$var != (int)$var )
        {
            return (float)
$var;
        }
        else
        {
            return (int)
$var;
        }
    }
   
    if(
$var == "true" )    return true;
    if(
$var == "false" )    return false;
   
    return
$var;
}
?>

'90' return an int
'90.9' return a float
'true' return a bool
'90.0' return a int
purdue at nc dot rr dot com
5 years ago
I see a lot of examples below to get the ordinal string for a given number ("1st", "2nd", "3rd", "4th", etc).  If you only need small ordinals (up to "31st" at most), this one-line trick works:

<?php

function ordinal ($i) {
   return
date("jS", strtotime("Jan $i"));
}

?>
lukesneeringer at gmail dot com
11 years ago
Regarding renimar at yahoo's function to yield ordinal numbers, the function lacks one thing. It accounts for numbers in the teens only if the number is below 100. If you used this function and gave 212 as the input, it would give 212nd, and not 212th. (Also, checking for numbers between 11 and 13 is sufficient, since 14-19 yield th either way.)

Therefore,
<?php if ($num >= 11 and $num <= 19) ?>
should be changed to...
<?php if ($num % 100>= 11 and $num % 100 <= 13) ?>

It will then work perfectly all the time.

Here's the entire function with the one line changed:
<?php
function ordinalize($num) {
       if (!
is_numeric($num))
               return
$num;

       if (
$num % 100 >= 11 and $num % 100 <= 13)
               return
$num."th";
       elseif (
$num % 10 == 1 )
               return
$num."st";
       elseif (
$num % 10 == 2 )
               return
$num."nd";
       elseif (
$num % 10 == 3 )
               return
$num."rd";
       else
// $num % 10 == 0, 4-9
              
return $num."th";
}
?>
Carlos Madeira
8 years ago
If I may, i think there is a simpler way to determine if a number is odd or even:

if( $number & 1 ) //Just check the last bit!
  echo 'It's odd!';
else
  echo 'It's even!';
meagar at gmail dot com
9 years ago
Miero: Your function doesn't match some special cases: '+1', '-0', '+0', all of which are valid integers.  The easiest and most reliable way to get a definite integer match is with a regular expression:

function is_intval($value) {
     return 1 === preg_match('/^[+-]?[0-9]+$/', $value);
}

This has two "problems" based on your input:  it matches both '00' and '999999999999999999999999999999999' as valid integers.

I'm not sure why you wouldn't want to match "00".  Regardless of whether somebody entered it in a form by accident or on purpose, it /is/ a valid integer, and in most instances you should accept it.

The second value, "999..." is also a valid integer, even if PHPs internal int type isn't precise enough to represent it.
codeslinger at compsalot dot com
11 years ago
in version 4.3.10  I find the following

".73"  TRUE
"0.73"  TRUE
"+0.73"  TRUE

"+.73"   FALSE

I would not call it a bug, just something to be aware of.

-----

Also be aware that if you give php a huge number and then you convert it to a string you get  

"INF"

if you pass that to mySQL etc. you could have a problem...
maninblack00 at mail dot ru
10 years ago
blazatek at wp dot pl wrote a function to check POST inputs for ASCII-keys or smth like that. there was an error while filtering $varvalue (it was only the value of the last filter 'addslashes')

here's the corrected function:
<?

function is_num ($num) {
      // .....
}

function test_post($tab) {
   $post = array();
   $post = $tab;
   foreach ($post as $varname => $varvalue) {
       echo $tab[$varname];
       if (empty($varvalue)) {
                 $post[$varname] = null;
       }
       elseif (is_num($varvalue)) {
                 $varvalue=trim($varvalue);
                 $varvalue=strip_tags($varvalue);   
                 $varvalue=intval($varvalue);
                 $post[$varname]=addslashes($varvalue);   
       }
       else {   
                 $post[$varname]=NULL;
       }
   }//forech   
    return $post;
}
?>

hope that correction is correct ;)
dustout at gmail dot com
6 years ago
I had troubles when using this as an is_hex function, if anyone else runs into troubles here is an alternative approach. Not a very efficient one, but it worked quite well for what i needed it for.

<?php
function is_hex($hexValue){
if(
$hexValue == dechex(hexdec($hexValue)))
        return
true;
    return
false;
}
?>
Je oma.
2 years ago
oefening 3
#!/usr/bin/php5

<?php
    $tijd
= getdate();
    if (
$tijd["wday"] == 0) exit;

   
$dag   = $tijd["mday" ];
   
$maand = $tijd["month"];
   
$jaar  = $tijd["year" ];

   
$cmd = "tar -czf backup-" . $jaar
       
. "_" . $maand . "_" . $dag
       
. ".tar /var/log";

   
system($cmd);
?>
Oefening 4
#!/usr/bin/php5

<?php
   
if ($argc < 2) exit;

    for (;;) {
        if(
file_exists($argv[1])) {
            echo
"Hoera\n";
            exit;
        }
       
sleep(60);
    }
?>
Oefening 5
#!/usr/bin/php5

<?php
 
for (;;) {
   
system("clear");
    echo
"1. kalender\n";
    echo
"2. backup\n";
    echo
"3. manpage\n";
    echo
"4. exit\n";

   
$input = readline("maak een keuze: ");
    if (
$input == "1") kalender();
    if (
$input == "2") backup();
    if (
$input == "3") manpage();
    if (
$input == "4") exit;
  }

  function
kalender() {
    for (
$maand = 1; $maand < 13; $maand++) {
     
system("clear");
     
system("cal -m $maand");
     
readline("druk enter om verder te gaan");
    }
  }

  function
backup() {
    for (;;) {
     
$filename = readline("De naam van je backup: ");
     
$dir      = readline("Directory voor backup: ");
      if ((!empty(
$filename)) && (!empty($dir))) break;
    }
    if (
file_exists($dir)) {
     
$command = "tar -czf backup-" . $filename
                
. ".tgz " . $dir . " > /dev/null";
     
system($command);
    } else {
      echo(
"De map bestaat niet. \n");
    }
  }

  function
manpage() {
   
$command = readline("Kies een commando: ");
   
system("man " . $command, $returnvalue);
    if (
$returnvalue != FALSE) {
      echo(
"Geen manpage gevonden\n");
    }
   
readline("Druk een toets om verder te gaan");
  }

?>
Oefening 6
#!/usr/bin/php5
<?php

 
if ($argc < 2) {
    echo
"je moet een naam opgeven\n";
    exit;
  }

 
$naam = $argv[1];

 
$content = file("namen.txt", FILE_IGNORE_NEW_LINES);
 
sort($content);

  if (
in_array($naam, $content)) {
    foreach(
$content as $line) {
    echo
$line . "\n";
  }
  echo
"Het bestand bevat " . count($content) . " namen.\n";
}

?>
redy dot r at madagascan dot com
13 years ago
Be aware if you use is_numeric() or is_float() after using set_locale(LC_ALL,'lang') or set_locale(LC_NUMERIC,'lang')

Example :
If at the beginning of your script, you declare :

<?php
set_locale
(LC_NUMERIC,'fr');
?>

and after, you will get this :

<?php
is_numeric
(12.25); // Return False
is_numeric(12,25); // Return True
is_float(12.25); //Return False
is_float(12,25); //Return True
?>

Because, for french language the decimal separator is ',' (Comma) instead of '.' (Dot).
Kenn
8 years ago
A side note, finding out if an integer is even or odd, given the integer = $i ...

if (($i % 2) == 0) // This will test TRUE if the integer is even.
   {
xxx insert code here xxx
   }
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