System.Int32.Parse Method

Converts the string representation of a number in a specified style to its 32-bit signed integer equivalent.

Syntax

public static int Parse (string s, System.Globalization.NumberStyles style)

Parameters

s
A string containing a number to convert.
style
A bitwise combination of the enumeration values that indicates the style elements that can be present in s. A typical value to specify is System.Globalization.NumberStyles.Integer.

Returns

A 32-bit signed integer equivalent to the number specified in s.

Exceptions

TypeReason
ArgumentNullException s is a null reference.
FormatException s is not in the correct style.
OverflowException s represents a number greater than int.MaxValue or less than int.MinValue.

Remarks

The style parameter defines the style elements (such as white space, the positive or negative sign symbol, or the thousands separator symbol) that are allowed in the s parameter for the parse operation to succeed. It must be a combination of bit flags from the System.Globalization.NumberStyles enumeration. Depending on the value of style, the s parameter may include the following elements:

[ws][$][sign][digits,]digits[.fractional_digits][e[sign]exponential_digits][ws]

Or, if style includes System.Globalization.NumberStyles.AllowHexSpecifier:

[ws]hexdigits[ws]

Items in square brackets ([ and ]) are optional. The following table describes each element.

ws

Optional white space. White space can appear at the beginning of s if style includes the System.Globalization.NumberStyles.AllowLeadingWhite flag, and it can appear at the end of s if style includes the System.Globalization.NumberStyles.AllowTrailingWhite flag.

$

A culture-specific currency symbol. Its position in the string is defined by the System.Globalization.NumberFormatInfo.CurrencyNegativePattern and System.Globalization.NumberFormatInfo.CurrencyPositivePattern properties of the current culture. The current culture's currency symbol can appear in s if style includes the System.Globalization.NumberStyles.AllowCurrencySymbol flag.

sign

An optional sign. The sign can appear at the beginning of s if style includes the System.Globalization.NumberStyles.AllowLeadingSign flag, and it can appear at the end of s if style includes the System.Globalization.NumberStyles.AllowTrailingSign flag. Parentheses can be used in s to indicate a negative value if style includes the System.Globalization.NumberStyles.AllowParentheses flag.

digits

fractional_digits

exponential_digits

A sequence of digits from 0 through 9. For fractional_digits, only the digit 0 is valid.

,

A culture-specific thousands separator symbol. The current culture's thousands separator can appear in s if style includes the System.Globalization.NumberStyles.AllowThousands flag.

.

A culture-specific decimal point symbol. The current culture's decimal point symbol can appear in s if style includes the System.Globalization.NumberStyles.AllowDecimalPoint flag. Only the digit 0 can appear as a fractional digit for the parse operation to succeed; if fractional_digits includes any other digit, an OverflowException is thrown.

e

The 'e' or 'E' character, which indicates that the value is represented in exponential notation. The s parameter can represent a number in exponential notation if style includes the System.Globalization.NumberStyles.AllowExponent flag.

hexdigits

A sequence of hexadecimal digits from 0 through f, or 0 through F.

A string with digits only (which corresponds to the System.Globalization.NumberStyles.None style) always parses successfully. Most of the remaining System.Globalization.NumberStyles members control elements that may be but are not required to be present in the input string. The following table indicates how individual System.Globalization.NumberStyles members affect the elements that may be present in s.

System.Globalization.NumberStyles.None

The digits element only.

System.Globalization.NumberStyles.AllowDecimalPoint

The decimal point ( . ) and fractional-digits elements.

System.Globalization.NumberStyles.AllowExponent

The s parameter can also use exponential notation.

System.Globalization.NumberStyles.AllowLeadingWhite

The ws element at the beginning of s.

System.Globalization.NumberStyles.AllowTrailingWhite

The ws element at the end of s.

System.Globalization.NumberStyles.AllowLeadingSign

The sign element at the beginning of s.

System.Globalization.NumberStyles.AllowTrailingSign

The sign element at the end of s.

System.Globalization.NumberStyles.AllowParentheses

The sign element in the form of parentheses enclosing the numeric value.

System.Globalization.NumberStyles.AllowThousands

The thousands separator ( , ) element.

System.Globalization.NumberStyles.AllowCurrencySymbol

The $ element.

System.Globalization.NumberStyles.Currency

All. The s parameter cannot represent a hexadecimal number or a number in exponential notation.

System.Globalization.NumberStyles.Float

The ws element at the beginning or end of s, sign at the beginning of s, and the decimal point ( . ) symbol. The s parameter can also use exponential notation.

System.Globalization.NumberStyles.Number

The ws, sign, thousands separator ( , ), and decimal point ( . ) elements.

System.Globalization.NumberStyles.Any

All styles, except s cannot represent a hexadecimal number.

If the System.Globalization.NumberStyles.AllowHexSpecifier flag is used, s must be a hexadecimal value. The only other flags that can be combined with the s parameter it are System.Globalization.NumberStyles.AllowLeadingWhite and System.Globalization.NumberStyles.AllowTrailingWhite. (The System.Globalization.NumberStyles enumeration includes a composite number style, System.Globalization.NumberStyles.HexNumber, that includes both white space flags.)

The s parameter is parsed using the formatting information in a System.Globalization.NumberFormatInfo object that is initialized for the current system culture. To specify the culture whose formatting information is used for the parse operation, call the int.Parse(string, System.Globalization.NumberStyles, IFormatProvider) overload.

Requirements

Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0