Pointers in C

Pointers

A pointer is a variable that stores the memory address of another variable, instead of a value directly. Pointers are what give C its famous low-level power — they let you access and modify memory directly, pass data efficiently to functions, and build dynamic data structures.

The & operator gets a variable's address, and * (dereferencing) gets the value stored at an address.

Syntax

type *pointerName;
pointerName = &variable;
*pointerName;   // dereference: get the value

Example

ptr stores the address of age; *ptr reads the value stored at that address.

#include <stdio.h>

int main() {
    int age = 25;
    int *ptr = &age;

    printf("Value: %d\n", age);
    printf("Address: %p\n", (void*)&age);
    printf("Via pointer: %d\n", *ptr);
    return 0;
}

Try it yourself

Copy this example into the C compiler and run it — try changing a value and see what happens.

Quick Quiz