c++ 指针（二）

发布时间：2020-12-16 09:20:05 所属栏目：百科来源：网络整理

导读：指针（4）指针数组 #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 ;} Value of va

指针

（4）指针数组

#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;
}

Value of var[0] = 10
Value of var[1] = 100
Value of var[2] = 200

指向整数的指针数组的声明：

int *ptr[MAX];

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

#include <iostream>
 
using namespace std;
const int MAX = 3;
 
int main ()
{
   int  var[MAX] = {10,200};
   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;
}

Value of var[0] = 10
Value of var[1] = 100
Value of var[2] = 200

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：

#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;
}

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",};

    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;
}

cout<<*names[i]<<endl; 输出结果为对应得指针数组的第一个字符，因为 *name 代表指向数组的第一个地址的值

#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;
    }
}

?char *names[MAX] 这种字符型的指针数组是存储指针的数组，但是在理解字符型指针数组的时候，可以将它理解为一个二维数组，如 const char *names[4] = {"Zara Ali","Hina Ali","Nuha Ali","Sara Ali",} 可以理解为一个 4 行 8 列的数组，可以用 cout << *(names[i] + j)<< endl 取出数组中的每个元素。

#include <iostream>

using namespace std;

const int MAX = 4;
int main ()
{
    const char *names[MAX] = {
        "Zara Ali",};

    for (int i = 0; i < MAX; i++)
        for (int j = 0; j < 8; j++)
        {
            cout << "Value of names[" << i << "] = ";
            cout << *(names[i] + j)<< endl;
        }
    return 0;
}

?结果：

Value of names[0] = Z Value of names[0] = a Value of names[0] = r Value of names[0] = a Value of names[0] = Value of names[0] = A Value of names[0] = l Value of names[0] = i Value of names[1] = H Value of names[1] = i Value of names[1] = n Value of names[1] = a Value of names[1] = Value of names[1] = A Value of names[1] = l Value of names[1] = i Value of names[2] = N Value of names[2] = u Value of names[2] = h Value of names[2] = a Value of names[2] = Value of names[2] = A Value of names[2] = l Value of names[2] = i Value of names[3] = S Value of names[3] = a Value of names[3] = r Value of names[3] = a Value of names[3] = Value of names[3] = A Value of names[3] = l Value

（编辑：李大同）

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