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Pointer to pointer
C language allows us to take pointer variables which can contain address of other pointer variables. In such a case, the concept of pointer to pointer is used. The pointer to pointer variable can be declared by prefixing the variable declaration with double asterisk sign.
Example
int **a;
Here, pointer variable a is pointer to pointer variable as it is prefixed with two asterisk signs.
| Program to demonstrate pointer to pointer. |
| #include<stdio.h> int main() {int a=10,*b,**c;b=&a; c=&b;printf(“\nb=%u”,b); printf(“\n*b=%d “,*b); printf(“\n*c=%u”,*c); printf(“\n**c=%d “,**c); return(0); |
| Output |
| b=65524 *b=10 *c=65524 **c=10 |
| Description |
| In the above program, c is pointer to pointer variable and it contains the address of other pointer variable b which further contains the address of normal variable a. *b refers to the value of a. *c refers to the address of a. **c refers to the value of variable a. |
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