How to Return Pointer from Function in C: Syntax and Examples

In C, you can return a pointer from a function by specifying the return type as a pointer type, for example int *. The function returns the address of a variable or dynamically allocated memory, allowing the caller to access or modify the data via the pointer.

Syntax

To return a pointer from a function, declare the function's return type as a pointer type. For example, int *functionName() means the function returns a pointer to an integer.

• Return type: Pointer type like int *, char *, etc.
• Function name: Your chosen function name.
• Return statement: Return the address of a variable or dynamically allocated memory.

c

int *functionName();

int *functionName() {
    int *ptr;
    // assign ptr to point to some int
    return ptr;
}

Example

This example shows a function that returns a pointer to a static integer variable. The main function prints the value using the returned pointer.

c

#include <stdio.h>

int *getPointer() {
    static int value = 42; // static to keep value valid after function ends
    return &value;
}

int main() {
    int *ptr = getPointer();
    printf("Value pointed to: %d\n", *ptr);
    return 0;
}

Output

Value pointed to: 42

Common Pitfalls

Returning a pointer to a local (non-static) variable is a common mistake because the variable's memory is freed when the function ends, leading to undefined behavior.

Always return pointers to static variables, dynamically allocated memory, or variables passed by reference.

c

/* Wrong: returning pointer to local variable */
int *wrong() {
    int local = 10;
    return &local; // local is destroyed after function ends
}

/* Correct: returning pointer to static variable */
int *correct() {
    static int value = 10;
    return &value;
}

Quick Reference

Concept	Description
Function return type	Declare as pointer type (e.g., int *)
Return value	Return address of static/dynamic variable
Avoid	Do not return pointer to local non-static variable
Use case	Access or modify data outside function scope

Key Takeaways

Declare the function return type as a pointer to return a pointer.

Return pointers to static or dynamically allocated variables to keep them valid.

Never return pointers to local non-static variables as they become invalid.

Use the returned pointer to access or modify data outside the function.

Static variables inside functions retain their value and address after function ends.