C程序显示指针与指针之间的关系
在C语言中，指向指针或双指针的指针是一个变量，用于保存另一个指针的地址。
宣言
下面给出的是指向指针的声明-
datatype ** pointer_name;
例如，int**p;
在此，p是指向指针的指针。
初始化
“＆”用于初始化。
例如，
int a = 10; int *p; int **q; p = &a;
存取中
间接运算符（*）用于访问
样例程序
以下是双指针的C程序-
#include输出结果main ( ){ int a = 10; int *p; int **q; p = &a; q = &p; printf("a =%d ",a); printf(" a value through pointer = %d", *p); printf(" a value through pointer to pointer = %d", **q); }
执行以上程序后，将产生以下结果-
a=10 a value through pointer = 10 a value through pointer to pointer = 10
示例
现在，考虑另一个C程序，该程序显示了指针与指针之间的关系。
#include输出结果void main(){ //Declaring variables and pointers// int a=10; int *p; p=&a; int **q; q=&p; //Printing required O/p// printf("Value of a is %d\n",a);//10// printf("Address location of a is %d\n",p);//address of a// printf("Value of p which is address location of a is %d\n",*p);//10// printf("Address location of p is %d\n",q);//address of p// printf("Value at address location q(which is address location of p) is %d\n",*q);//address of a// printf("Value at address location p(which is address location of a) is %d\n",**q);//10// }
执行以上程序后，将产生以下结果-
Value of a is 10 Address location of a is 6422036 Value of p which is address location of a is 10 Address location of p is 6422024 Value at address location q(which is address location of p) is 6422036 Value at address location p(which is address location of a) is 10