What are the specific uses of pointer to pointer?

A pointer to pointer variable can hold the address of another pointer variable. The Syntax is as follow: type** variable; Example:: //function prototype void func(int** ppInt); int main() { int nvar=2; int* pvar=&nvar; func(&pvar); .... return 0; }

One more important use of pointer-to-pointer is for creating multi-dimensional array dynamically, see See the related links.