std::basic_string::operator+=
From cppreference.com
< cpp | string | basic string
basic_string& operator+=( const basic_string& str );
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(1) | |
basic_string& operator+=( CharT ch );
|
(2) | |
basic_string& operator+=( const CharT* s );
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(3) | |
basic_string& operator+=( std::initializer_list<CharT> ilist );
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(4) | (since C++11) |
Appends additional characters to the string.
1) Appends string
str
2) Appends character
ch
3) Appends the null-terminated character string pointed to by
s
.
4) Appends characters in the initializer list
ilist
.
Contents |
[edit] Parameters
str | - | string to append |
ch | - | character value to append |
s | - | pointer to a null-terminated character string to append |
ilist | - | initializer list with the characters to append |
[edit] Return value
*this
[edit] Complexity
1) linear in size of
str
2) constant
3) linear in size of
s
4) linear in size of
ilist
[edit] Exceptions
If an exception is thrown for any reason, this function has no effect (strong exception guarantee). (since C++11)
If the operation would result in size() > max_size()
, throws std::length_error.
[edit] Notes
Owing to Implicit conversions, operator+= might accept values of unwanted types.
[edit] Example
Run this code
#include <iostream> #include <iomanip> #include <string> int main() { std::string str; str.reserve(50); //reserves sufficient storage space to avoid memory reallocation std::cout << std::quoted(str) << '\n'; //empty string str += "This"; std::cout << std::quoted(str) << '\n'; str += std::string(" is "); std::cout << std::quoted(str) << '\n'; str += 'a'; std::cout << std::quoted(str) << '\n'; str += {' ','s','t','r','i','n','g','.'}; std::cout << std::quoted(str) << '\n'; str += 76.85; // equivalent to str += static_cast<char>(76.85), might not be the intent std::cout << std::quoted(str) << '\n'; }
Output:
"" "This" "This is " "This is a" "This is a string." "This is a string.L"
[edit] See also
assign characters to a string (public member function) |