Append

#include <cassert>
#include <string>
using std::string;
void main() {
    string s1;    // empty
    string s2;    // empty
    s1 += "Fred"; // From null terminated char*
    s1 += 'a';    // Becomes "Freda"
    s2 += s1;     // Of course, s2 becomes "Freda"
    // Additional append functions corresponding
    // to existing constructors:
    s1.append( "Hello", 4);
    assert( s1 == "FredaHell" );
    s1.append( 6, 'a' );
    assert( s1 == "FredaHellaaaaaa" );
    // Append portion of s2 that begins at the position 2
    // and up to 5 characters. However, it takes less
    // than 5 because the end of s2 is reached sooner:
    s1.append( s2, 2, 5 );  // appends "eda"
    assert( s1 == "FredaHellaaaaaaeda" );
}