C + + operator overloading

What is overloading: Let the operator have the function that you want.

#ifndef _array_h_#define_array_h_classarray{Private:    intmlength; int*Mspace; Public: Array (intlength); Array (Constarray&obj); intlength (); voidSetData (intIndexintvalue); intGetData (intindex); ~Array (); //overloading the [] operator, taking values from the array class (int type)    int&operator[](inti); //overloaded operator =, copy array classarray&operator= (Array &AA); //overloaded operator = =, compares two array classes for the same    BOOL operator= = (Array &aa);};#endif

Array.h

#include"iostream"#include"Array.h"using namespacestd; Array::array (intlength) {    if(Length <0) {length=0; } mlength=length; Mspace=New int[mlength];} Array::array (Constarray&obj) {Mlength=obj.mlength; //open up mlength-sized memory space MspaceMspace =New int[Mlength];  for(intI=0; i<mlength; i++) {Mspace[i]=Obj.mspace[i]; }}intarray::length () {returnmlength;}voidArray::setdata (intIndexintvalue) {Mspace[index]=value;}intArray::getdata (intindex) {    returnMspace[index];} Array::~Array () {mlength= -1; Delete[] mspace;}int& Array::operator[](inti) {    return  This-mspace[i];} Array& Array::operator= (Array &AA) {    inti =0; if( This->mspace! =NULL) {         Free(Mspace); }     This->mlength =aa.mlength; Mspace=New int[Mlength];  for(i=0; i<mlength; i++)    {        (* This) [I] =Aa[i]; }    return(* This);}BOOLArray::operator= = (Array &AA) {    inti =0; if( This->mlength! =aa.mlength) {return false; }     for(i=0; i< This->mlength; i++)    {        if(Mspace[i]! =Aa.mspace[i]) {            return false; }    }    return true;}

Array.cpp

#include"iostream"#include"Array.h"using namespacestd;intMain () {Array A1 (Ten);  for(intI=0; I<a1.length (); i++)    {        //A1.setdata (i, I); //Overwrite [] function oneA1[i] =i; }         for(intI=0; I<a1.length (); i++)    {        //printf ("Array%d:%d\n", I, A1.getdata (i));printf"Array%d:%d\n", I, a1[i]); } Array A2=A1; Array A3 ( -); A3= A2;//overloaded operator = function two     for(intI=0; I<a2.length (); i++)    {        //printf ("Array%d:%d\n", I, A2.getdata (i));printf"Array%d:%d\n", I, a2[i]); } a1[9] = +; if(A1==A2)//overloaded operator = = function three{cout<<"two arrays are exactly equal! "<<Endl; }    Else{cout<<"two arrays are not equal! "<<Endl; }    return 0;}

ArrayText.cpp

Overloaded operator Note points:

1. There are two methods for overloading operators:1> using member functions (most of them) 2> with global functions (friend functions): When the source code of the object calling this operator cannot be obtained, such as: Overloading << operator

// The friend function implements the left shift operator, prints the object friend Ostream &operator<< (ostream & Out, Complex &cc);

2. Front + + (-) and post + + (--) Attention points

// The class member function implements the predecessor + + and returns a reference to itself Complex &operator+ +()// class member functions implement Post + +, the return value is local object operator+ + ( int )

3. Special Note: when overloading = or the [] operator, the return is a reference, and only the reference can be an lvalue. It is also important to note that the caller's original pointer field is empty, not empty, and needs to be released!

C + + operator overloading