C++中this指针用法详解及实例

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#ifndef TEST_H
#define TEST_H

class Test 
{
public:
  explicit Test( int = 0 ); // default constructor
  void print() const;
private:
  int x;
}; // end class Test

#endif /* TEST_H */

#include "Test.h"
#include <iostream>
using namespace std;

// constructor
Test::Test( int value ) : x( value ){}

// print x using implicit and explicit this pointers;
// the parentheses around *this are required
void Test::print() const  
{
  // implicitly use the this pointer to access the member x
  cout << "    x = " << x;
  // explicitly use the this pointer and the arrow operator
  // to access the member x
  cout << "\n this->x = " << this->x;
  // explicitly use the dereferenced this pointer and 
  // the dot operator to access the member x
  cout << "\n(*this).x = " << ( *this ).x << endl;
} // end function print

#include "Test.h"
int main()
{
  Test testObject( 12 ); // instantiate and initialize testObject
  testObject.print();
  return 0;
} // end main

class Time 
{
public:
  //...此处省略若干行非重点部分
  Time &setHour( int ); // set hour
  Time &setMinute( int ); // set minute
  Time &setSecond( int ); // set second

  //...此处省略若干行非重点部分
private:
  unsigned int hour; // 0 - 23 (24-hour clock format)
  unsigned int minute; // 0 - 59
  unsigned int second; // 0 - 59
}; // end class Time

// set hour value
Time &Time::setHour( int hour ) // note Time & return
{
  if ( hour >= 0 && hour < 24 )
   this->hour = hour;
  else
   throw invalid_argument( "hour must be 0-23" );

  return *this; // enables cascading
} // end function setHour

// set minute 和 set second写法类似

//省略非重要的预处理指令和using命令
#include "Time.h" // Time class definition

int main()
{
  Time t; // create Time object

  // cascaded function calls
  t.setHour( 18 ).setMinute( 30 ).setSecond( 22 );

  //省略其余非重要部分
} // end main