c语言指针示例_C程序演示双指针示例（指向指针的指针）

c语言指针示例

In this program, we have to declare, assign and access a double pointer (pointer to pointer) in C.

在此程序中，我们必须在C中声明，分配和访问双指针(指向指针的指针)。

As we know that, pointers are the special type of variables that are used to store the address of another variable.

众所周知，指针是变量的特殊类型，用于存储另一个变量的地址。

But, when we need to store the address of a pointer variable, we cannot assign it in a pointer variable. To store address of a pointer variable, we use a double pointer which is also known as pointer to pointer.

但是 ，当我们需要存储指针变量的地址时，我们不能将其分配给指针变量。 为了存储指针变量的地址，我们使用了一个双指针，也称为指针指针 。

In this C program, we will understand how to declare, assign and access a double pointer (pointer to pointer)?

在此C程序中，我们将了解如何声明，分配和访问双指针(指向指针的指针)？

双指针(指向指针的指针)的C程序 (C program for double pointer (pointer to pointer))

/*C program to demonstrate example of double pointer (pointer to pointer).*/
#include 
 
int main()
{
     
    int a;          //integer variable
    int *p1;            //pointer to an integer
    int **p2;           //pointer to an integer pointer
     
    p1=&a;          //assign address of a
    p2=&p1;         //assign address of p1
     
    a=100;          //assign 100 to a
     
    //access the value of a using p1 and p2
    printf("\nValue of a (using p1): %d",*p1);
    printf("\nValue of a (using p2): %d",**p2);
     
    //change the value of a using p1
    *p1=200;
    printf("\nValue of a: %d",*p1);
    //change the value of a using p2
    **p2=200;
    printf("\nValue of a: %d",**p2);
     
    return 0;
}

Output

输出量

    Value of a (using p1): 100
    Value of a (using p2): 100
    Value of a: 200
    Value of a: 200

翻译自: https://www.includehelp.com/c-programs/c-pointer-program-to-demonstrate-example-of-pointer-to-pointer-double-pointer.aspx

c语言指针示例