#include <iostream>

using namespace std;

void swap1(int &p, int &q)
{// 引用数值交换
  int temp;
  temp = p;
  p = q;
  q = temp;
}

void swap2(int *p, int *q)
{// 指针数值交换
  int temp;
  temp = *p;
  *p = *q;
  *q = temp;
}

void Getmemory1(char **p, int num)
{
  *p = (char *)malloc(sizeof(char) * num);
}
char *Getmemory2(char *p, int num)
{
  p = (char *)malloc(sizeof(char) * num);
  return p;
}
void Getmemory(int *z)
{
  *z = 5201314;
}


const char* strA()
{
  char *str = "Hello John!";      //分配一个全局数组，数据不可修改
  return str;
}
const char* strA1()
{
  static char str[] = "Hi, John!";//分配一个局部数组
  return str;
}

int main(int argc, char *argv[])
{
  int iv = 520;
  int &ivv = iv;        // 声明引用的同时需要进行初始化
  const int iv1 = 1314; // const 常量赋值时，必须同时初始化
  cout << "引用       : " << ivv << "," << iv << endl;
  cout << "const 常量 : " << iv1 << endl << endl;

  int a = 1, b = 2;
  cout << "原始数值     : " << " a = " << a << "," << " b = " << b << endl;
  swap1(a, b);
  cout << "引用数值交换 : " << " a = " << a << "," << " b = " << b << endl;
  swap2(&a, &b);
  cout << "指针数值交换 : " << " a = " << a << "," << " b = " << b << endl;
  cout << endl;

  char *str1 = NULL;
  Getmemory1(&str1, 100);
  strcpy(str1, "John");
  char *str2 = NULL;
  str2 = Getmemory2(str2, 100);
  strcpy(str2, "tian");
  cout << "指针的指针分配内存空间 : " << str1 << endl;
  cout << "返回的指针分配内存空间 : " << str2 << endl;

  int v = 0;
  Getmemory(&v);
  cout << "整数的指针分配内存空间 : " << v << endl;
  cout << endl;

  const char * s1 = strA();
  const char * s2 = strA1();
  cout << "全局数组 : " << s1 << endl;
  cout << "局部数组 : " << s2 << endl;
  cout << endl;

  return 0;
}


C++ 引用,指针_指针