How to return a Pointer from a Function in C (original) (raw)

Last Updated : 19 Aug, 2020

Pointers in C programming language is a variable which is used to store the memory address of another variable. We can pass pointers to the function as well as return pointer from a function. But it is not recommended to return the address of a local variable outside the function as it goes out of scope after function returns.

**Program 1:**The below program will give segmentation fault since 'A' was local to the function:

C `

// C program to illustrate the concept of // returning pointer from a function #include <stdio.h>

// Function returning pointer int* fun() { int A = 10; return (&A); }

// Driver Code int main() { // Declare a pointer int* p;

// Function call
p = fun();

printf("%p\n", p);
printf("%d\n", *p);
return 0;

}

`

**Output:**Below is the output of the above program: Explanation:

The main reason behind this scenario is that compiler always make a stack for a function call. As soon as the function exits the function stack also gets removed which causes the local variables of functions goes out of scope.

Static Variables have a property of preserving their value even after they are out of their scope. So to execute the concept of returning a pointer from function in C you must define the local variable as a static variable.

Program 2:

C `

// C program to illustrate the concept of // returning pointer from a function #include <stdio.h>

// Function that returns pointer int* fun() { // Declare a static integer static int A = 10; return (&A); }

// Driver Code int main() { // Declare a pointer int* p;

// Function call
p = fun();

// Print Address
printf("%p\n", p);

// Print value at the above address
printf("%d\n", *p);
return 0;

}

`