string::operator+
Illustrates how to use the string::operator+ STL function in Visual C++.
template<class _E, class _TYPE, class _A> inline
basic_string<_E, _TYPE, _A>
operator+(
const basic_string<_E, _TYPE, _A>& LString,
const _E *RCharArray
);
template<class _E, class _TYPE, class _A> inline
basic_string<_E, _TYPE, _A>
operator+(
const _E *LCharArray,
const basic_string<_E, _TYPE, _A>& RString
);
template<class _E, class _TYPE, class _A> inline
basic_string<_E, _TYPE, _A>
operator+(
const basic_string<_E, _TYPE, _A>& LString,
const _E RChar
);
template<class _E, class _TYPE, class _A> inline
basic_string<_E, _TYPE, _A>
operator+(
const _E LChar,
const basic_string<_E, _TYPE, _A>& RString
);
template<class _E, class _TYPE, class _A> inline
basic_string<_E, _TYPE, _A>
operator+(
const basic_string<_E, _TYPE, _A>& LString,
const basic_string<_E, _TYPE, _A>& RString
);
Remarks
备注
The class/parameter names in the prototype do not match the version in the header file. Some have been modified to improve readability.
There are five versions of the string::operator+ function. Two functions are used to concatenate a null-terminated character array and a basic_string. Two functions are used to concatenate a character and a basic_string. The last function is used to concatenate two basic_string variables.
Example
// StringPlus.cpp
// compile with: /EHsc
// Illustrates how to use the operator+ to concatenate
// a null-terminated character array and a basic_string,
// how to concatenate a character and a basic_string,
// and how to concatenate two basic_string variables.
//
// Functions:
//
// operator+ : Concatenates a null-terminated character array and
// a basic_string.
// operator+ : Concatenates a character array and a basic_string.
// operator+ : Concatenates two basic_string variables.
//////////////////////////////////////////////////////////////////////
#pragma warning(disable:4786)
#include <string>
#include <iostream>
using namespace std ;
int main()
{
string result;
string S1="ABC";
string S2="DEF";
char CP1[]="GHI";
char C='J';
cout << "S1 is " << S1 << endl;
cout << "S2 is " << S2 << endl;
cout << "CP1 is " << CP1 << endl;
cout << "C is " << C << endl;
result=S1+CP1; // Function 1 (ABCGHI)
cout << "S1+CP1 is " << result << endl;
result=CP1+S1; // Function 2 (GHIABC)
cout << "CP1+S1 is " << result << endl;
result=S1+S2; // Function 3 (ABCDEF)
cout << "S1+S2 is " << result << endl;
result=S1+C; // Function 4 (ABCJ)
cout << "S1+C is " << result << endl;
result=C+S1; // Function 5 (JABC)
cout << "C+S1 is " << result << endl;
}
S1 is ABC
S2 is DEF
CP1 is GHI
C is J
S1+CP1 is ABCGHI
CP1+S1 is GHIABC
S1+S2 is ABCDEF
S1+C is ABCJ
C+S1 is JABC
Requirements
Header: <string>