The problem of coincidence of parameter names and member variable names of member functions in C + +

One day when writing classes suddenly thought of this problem, the following to explain how to solve the problem.

Define a class:

class test{public:    void  setnum ();     void getnum (); Private :     int num;}; void Test::setnum () {    ten;} void Test::getnum () {    printf ("%d\n", num);}

Run:

int Main () {        test one;       One.setnum ();       One.getnum ();           return 0 ;}

Console output 100, which indicates that member functions can be directly modified by the member variables without relying on parameter arguments .

Next we can make a change to the member function of the assignment:

#include <stdio.h>#include<windows.h>#include<mysql.h>classtest{ Public:    voidSetnum (intx); voidgetnum ();Private:    intnum;};voidTest::setnum (intx) {num=x;}voidTest::getnum () {printf ("%d\n", num);}intMain () {test one; One.setnum ( -);          One.getnum (); return 0;}

Console output 100

Let's make another change:

class test{public:    void setnum (int  num);     void getnum (); Private :     int num;}; void test::setnum (int  num) {    = num;}

At this point in the run, the member function that found the assignment is not running at all.

The solution is:

void test::setnum (int  num) {    this->num = num;} 

Use this pointer to distinguish between the two variables.

The problem of coincidence of parameter names and member variable names of member functions in C + +