Pointers – Let us C

Pointers to Functions

Pravesh Agrawal — Sat, 02 Dec 2023 11:16:57 +0000

#include 

// Function that adds two numbers
int add(int a, int b) {
    return a + b;
}

int main() {
    // Pointers to functions
    int (*sum)(int, int);
    sum = add;

    printf("Sum: %d\n", sum(3, 5));

    return 0;
}

Dynamic Memory Allocation with Pointers

Pravesh Agrawal — Sat, 02 Dec 2023 11:16:43 +0000

#include 
#include 

int main() {
    // Dynamic memory allocation with pointers
    int *dynamicArray;
    int size;

    printf("Enter the size of the array: ");
    scanf("%d", &size);

    dynamicArray = (int *)malloc(size * sizeof(int));

    if (dynamicArray == NULL) {
        printf("Memory allocation failed.\n");
        return 1;
    }

    // Use the dynamically allocated array

    // Free the allocated memory
    free(dynamicArray);

    return 0;
}

Pointers and Functions

Pravesh Agrawal — Sat, 02 Dec 2023 11:16:28 +0000

#include 

// Function that swaps two integers using pointers
void swap(int *a, int *b) {
    int temp = *a;
    *a = *b;
    *b = temp;
}

int main() {
    // Pointers and functions
    int x = 5, y = 10;

    printf("Before swapping: x = %d, y = %d\n", x, y);

    swap(&x, &y);

    printf("After swapping: x = %d, y = %d\n", x, y);

    return 0;
}

Pointer Arithmetic

Pravesh Agrawal — Sat, 02 Dec 2023 11:16:13 +0000

#include 

int main() {
    // Pointer arithmetic
    int numbers[] = {1, 2, 3, 4, 5};
    int *ptr = numbers;

    printf("First element: %d\n", *ptr);
    printf("Second element: %d\n", *(ptr + 1));
    printf("Third element: %d\n", *(ptr + 2));

    return 0;
}

Simple Pointer Declaration and Use

Pravesh Agrawal — Sat, 02 Dec 2023 11:15:59 +0000

#include 

int main() {
    // Simple pointer declaration and use
    int number = 42;
    int *ptr = &number;

    printf("Value of number: %d\n", number);
    printf("Address of number: %p\n", (void *)&number);
    printf("Value of pointer (address of number): %p\n", (void *)ptr);
    printf("Value pointed by pointer: %d\n", *ptr);

    return 0;
}