Wednesday 21 September 2016

Pointer

A Pointer in C is a way to share a memory address among different contexts (primarily functions). They are primarily used whenever a function needs to modify the content of a variable, of which it doesn't have ownership.

In order to access the memory address of a variable, , we need to prepend it with sign. E.g., &val returns the memory address of .

This memory address is assigned to a pointer and can be shared among various functions. E.g. will assign the memory address of to pointer . To access the content of the memory to which the pointer points, prepend it with a *. For example, *p will return the value reflected by and any modification to it will be reflected at the source ().
void increment(int *v) {
    (*v)++;
}

int main() {
    int a;
    scanf("%d", &a);
    increment(&a);
    printf("%d", a);
    return 0;
}  

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