How to Sort an Array in C - Step by Step Examples

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How to Sort an Array in C ?

Answer

To sort an array in C, you can use the qsort() function from the stdlib.h library.

✐ Examples

1 Sort Integer Array in Ascending Order

In this example,

We create an integer array named numbers with values 5, 2, 8, 1, 6.
We define a compare function compare that compares two integers.
We use the qsort() function with our compare function to sort the array in ascending order.
Finally, we print the sorted array numbers to the console.

C Program

#include <stdio.h>
#include <stdlib.h>

int compare(const void *a, const void *b) {
    return (*(int*)a - *(int*)b);
}

int main() {
    int numbers[] = {5, 2, 8, 1, 6};
    int n = sizeof(numbers) / sizeof(numbers[0]);
    qsort(numbers, n, sizeof(int), compare);
    printf("Sorted array in ascending order: ");
    for (int i = 0; i < n; i++) {
        printf("%d ", numbers[i]);
    }
    return 0;
}

Output

Sorted array in ascending order: 1 2 5 6 8

2 Sort Integer Array in Descending Order

In this example,

We create an integer array named numbers with values 5, 2, 8, 1, 6.
We define a compare function compare that compares two integers in reverse order.
We use the qsort() function with our reverse compare function to sort the array in descending order.
Finally, we print the sorted array numbers to the console.

C Program

#include <stdio.h>
#include <stdlib.h>

int compare(const void *a, const void *b) {
    return (*(int*)b - *(int*)a);
}

int main() {
    int numbers[] = {5, 2, 8, 1, 6};
    int n = sizeof(numbers) / sizeof(numbers[0]);
    qsort(numbers, n, sizeof(int), compare);
    printf("Sorted array in descending order: ");
    for (int i = 0; i < n; i++) {
        printf("%d ", numbers[i]);
    }
    return 0;
}

Output

Sorted array in descending order: 8 6 5 2 1

Summary

In this tutorial, we learned How to Sort an Array in C language with well detailed examples.

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