std::basic_string<CharT,Traits,Allocator>:: append

Appends additional characters to the string.

Parameters

Return value

* this

Complexity

There are no standard complexity guarantees, typical implementations behave similar to std::vector::insert() .

Exceptions

If the operation would result in size ( ) > max_size ( ) , throws std::length_error .

If an exception is thrown for any reason, this function has no effect ( strong exception safety guarantee ).

Example

#include <iostream>
#include <string>
 
int main()
{
    std::basic_string<char> str = "string";
    const char* cptr = "C-string";
    const char carr[] = "Two and one";
 
    std::string output;
 
    // 1) Append a char 3 times. 
    // Notice, this is the only overload accepting chars.
    output.append(3, '*');
    std::cout << "1) " << output << '\n';
 
    // 2) Append a whole string
    output.append(str);
    std::cout << "2) " << output << '\n';
 
    // 3) Append part of a string (last 3 letters, in this case)
    output.append(str, 3, 3);
    std::cout << "3) " << output << '\n';
 
    // 4) Append part of a C-string
    // Notice, because `append` returns *this, we can chain calls together
    output.append(1, ' ').append(carr, 4);
    std::cout << "4) " << output << '\n';
 
    // 5) Append a whole C-string
    output.append(cptr);
    std::cout << "5) " << output << '\n';
 
    // 6) Append range
    output.append(&carr[3], std::end(carr));
    std::cout << "6) " << output << '\n';
 
    // 7) Append initializer list
    output.append({' ', 'l', 'i', 's', 't'});
    std::cout << "7) " << output << '\n';
}

1) ***
2) ***string
3) ***stringing
4) ***stringing Two 
5) ***stringing Two C-string
6) ***stringing Two C-string and one
7) ***stringing Two C-string and one list

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

See also