C++ 指针与数组

指针和数组具有密切关系。实际上，在许多情况下，指针和数组是可以互换的。例如，一个指向数组开头的指针可以通过使用指针算术或数组索引的方式来访问该数组。考虑以下程序−

#include <iostream>

using namespace std;
const int MAX = 3;

int main () {
   int  var[MAX] = {10, 100, 200};
   int  *ptr;

   // let us have array address in pointer.
   ptr = var;

   for (int i = 0; i < MAX; i++) {
      cout << "Address of var[" << i << "] = ";
      cout << ptr << endl;

      cout << "Value of var[" << i << "] = ";
      cout << *ptr << endl;

      // point to the next location
      ptr++;
   }

   return 0;
}

当上述代码被编译和执行时，它产生的结果类似于以下内容 –

Address of var[0] = 0xbfa088b0
Value of var[0] = 10
Address of var[1] = 0xbfa088b4
Value of var[1] = 100
Address of var[2] = 0xbfa088b8
Value of var[2] = 200

然而，指针和数组并不完全可以互相替换。例如，考虑以下程序 –

#include <iostream>

using namespace std;
const int MAX = 3;

int main () {
   int  var[MAX] = {10, 100, 200};

   for (int i = 0; i < MAX; i++) {
      *var = i;    // This is a correct syntax
      var++;       // This is incorrect.
   }

   return 0;
}