C++ 指针数组
C++ 指针在我们讲解指针数组的概念之前，先让我们来看一个实例，它用到了一个由 3 个整数组成的数组：
实例
#include <iostream>
using namespace std;
const int MAX = 3;
int main ()
{
int var[MAX] = {10, 100, 200};
for (int i = 0; i < MAX; i++)
{
cout << "Value of var[" << i << "] = ";
cout << var[i] << endl;
}
return 0;
}
当上面的代码被编译和执行时，它会产生下列结果：
Value of var[0] = 10 Value of var[1] = 100 Value of var[2] = 200
可能有一种情况，我们想要让数组存储指向 int 或 char 或其他数据类型的指针。下面是一个指向整数的指针数组的声明：
int *ptr[MAX];
在这里，把 ptr 声明为一个数组，由 MAX 个整数指针组成。因此，ptr 中的每个元素，都是一个指向 int 值的指针。下面的实例用到了三个整数，它们将存储在一个指针数组中，如下所示：
实例
#include <iostream>
using namespace std;
const int MAX = 3;
int main ()
{
int var[MAX] = {10, 100, 200};
int *ptr[MAX];
for (int i = 0; i < MAX; i++)
{
ptr[i] = &var[i]; // 赋值为整数的地址
}
for (int i = 0; i < MAX; i++)
{
cout << "Value of var[" << i << "] = ";
cout << *ptr[i] << endl;
}
return 0;
}
当上面的代码被编译和执行时，它会产生下列结果：
Value of var[0] = 10 Value of var[1] = 100 Value of var[2] = 200
您也可以用一个指向字符的指针数组来存储一个字符串列表，如下：
实例
#include <iostream>
using namespace std;
const int MAX = 4;
int main ()
{
const char *names[MAX] = {
"Zara Ali",
"Hina Ali",
"Nuha Ali",
"Sara Ali",
};
for (int i = 0; i < MAX; i++)
{
cout << "Value of names[" << i << "] = ";
cout << names[i] << endl;
}
return 0;
}
当上面的代码被编译和执行时，它会产生下列结果：
Value of names[0] = Zara Ali Value of names[1] = Hina Ali Value of names[2] = Nuha Ali Value of names[3] = Sara Ali
char *names[MAX] 是指针数组, 它的本质是存储指针的数组, 既存储 char 类型的指针的数组, 数组内的每个元素都是一个指针指向一个存储 char 类型的地址:
#include <iostream> using namespace std; const int MAX = 4; int main(int argc, const char * argv[]) { const char *names[MAX] = { "Zara Ali", "Hina Ali", "Nuha Ali", "Sara Ali", }; for (int i = 0; i < MAX; i++) { cout << " --- names[i] = " << names[i] << endl; cout << " --- *names[i] = " << *names[i] << endl; cout << endl; cout << " --- (*names[i] + 1) = " << (*names[i] + 1) << endl; cout << " --- (char)(*names[i] + 1) = " << (char)(*names[i] + 1) << endl; cout << " ------------------------------------ " << endl << endl << endl << endl; } return 0; }实例:
/* -------- Pointer.cpp -------- */ #include <iostream> using namespace std; void pointerArray(); void pointerArray4Char(); const int MAX = 3; int main(void){ // pointerArray(); pointerArray4Char(); return 0; } void pointerArray(){ int var[MAX] = {20,30,40}; int *ptr[MAX]; for(int i = 0; i < MAX; i++){ ptr[i] = &var[i];//赋值为整数的地址 } for(int i = 0; i < MAX; i++){ cout << "Value of var[" << i << "] = "; cout << *ptr[i] <<endl; } } /** * 用一个指向字符的指针数组来存储一个字符串列表 * Value of names[0] = sun; */ void pointerArray4Char(){ const char *names[MAX] = { "sun","bin","sunbin" }; for(int i = 0;i < MAX;i++){ cout <<"Value of names[" << i << "] = ";//输出字符串的值 cout << names[i] << endl; cout <<"Value of *names[" << i << "] = ";//输出指针所指向字符串首地址的值 cout << *names[i] << endl; cout <<"Value of *names[" << i << "]+1 = ";//输出ascii码值 cout << *names[i]+1 << endl; cout <<"Value of *(names[" << i << "]+1) = ";//输出指针所指向字符串首地址上一位的值 cout << *(names[i]+1) << endl; } }