C++ examples for Class:Operator Overload
Overloaded '+' operator concatenates strings for custom string class
#include <iostream> using namespace std; #include <string.h> //for strcpy(), strcat() #include <stdlib.h> //for exit() class String/*from w ww . j a v a 2 s. co m*/ { private: enum { SZ=80 }; //size of String objects char str[SZ]; //holds a string public: String() //constructor, no args { strcpy(str, ""); } String( char s[] ) //constructor, one arg { strcpy(str, s); } void display() const //display the String { cout << str; } String operator + (String ss) const //add Strings { String temp; //make a temporary String if( strlen(str) + strlen(ss.str) < SZ ) { strcpy(temp.str, str); //copy this string to temp strcat(temp.str, ss.str); //add the argument string } else { cout << "\nString overflow"; exit(1); } return temp; //return temp String } }; int main() { String s1 = "\nMerry Christmas! "; //uses constructor 2 String s2 = "Happy new year!"; //uses constructor 2 String s3; //uses constructor 1 s1.display(); s2.display(); s3.display(); s3 = s1 + s2; //add s2 to s1, // assign to s3 s3.display(); cout << endl; return 0; }