basic_string::operator+=

Appends characters to a string.

basic_string<CharType, Traits, Allocator>& operator+=(
   value_type _Ch
);
basic_string<CharType, Traits, Allocator>& operator+=(
   const value_type* _Ptr
);
basic_string<CharType, Traits, Allocator>& operator+=(
   const basic_string<CharType, Traits, Allocator>& _Right
);

Parameters

• _Ch
  The character to be appended.

• _Ptr
  The characters of the C-string to be appended.

• _Right
  The characters of the string to be appended.

Return Value

A reference to the string object that is being appended with the characters passed by the member function.

Remarks

Characters may be appended to a string using the operator+= or the member functions append or push_back. The operator+= appends single-argument values while the multiple argument append member function allows a specific part of a string to be specified for adding.

Example

// basic_string_op_app.cpp
// compile with: /EHsc
#include <string>
#include <iostream>

int main( ) 
{
   using namespace std;

   // The first member function
   // appending a single character to a string
   string str1a ( "Hello" );
   cout << "The original string str1 is: " << str1a << endl;
   str1a +=  '!' ;
   cout << "The string str1 appended with an exclamation is: " 
        << str1a << endl << endl;

   // The second member function
   // appending a C-string to a string
   string  str1b ( "Hello " );
   const char *cstr1b = "Out There";
   cout << "The C-string cstr1b is: " << cstr1b << endl;
   str1b +=  cstr1b;
   cout << "Appending the C-string cstr1b to string str1 gives: " 
        << str1b << "." << endl << endl;

   // The third member function
   // appending one string to another in two ways,
   // comparing append and operator [ ]
   string str1d ( "Hello " ), str2d ( "Wide " ), str3d ( "World" );
   cout << "The string str2d is: " << str2d << endl;
   str1d.append ( str2d );
   cout << "The appended string str1d is: " 
        << str1d << "." << endl;
   str1d += str3d;
   cout << "The doubly appended strig str1 is: " 
        << str1d << "." << endl << endl;
}

The original string str1 is: Hello
The string str1 appended with an exclamation is: Hello!

The C-string cstr1b is: Out There
Appending the C-string cstr1b to string str1 gives: Hello Out There.

The string str2d is: Wide 
The appended string str1d is: Hello Wide .
The doubly appended strig str1 is: Hello Wide World.

Requirements

Header: <string>

Namespace: std

See Also

Concepts

basic_string Class

basic_string Members