Sorting an Array in C

For sorting an array, we have used the qsort function. This function provides the implementation of quicksort algorithm to sort the elements of an array.

Syntax of the function:
qsort(array, sizeof(array), sizeof(type), comparison_fn).

In the example, we have created a comparison function sort to compare two elements. For this we have passed two parameters (x and y ) which are pointers to elements and will return an int value by comparing them. This method compares each pair of elements. This function can be declared as:
int sort (const void * x, const void * y );

(*(int*)x - *(int*)y)- The parameters x and y checks for each pair of elements considering the elements as x and y. If x is found greater than y, then x goes before y otherwise, x goes after y. In case if x = y, then it remains on the same position.

- This header file stands for standard library which includes functions involving String, Memory, Environment, Sorting and Searching, Math and Multibyte.

Here is the code:

ARRAYSOR.C

#include #include #include int array[] = { 90, 3, 33, 28, 80, 49, 8, 30, 36, 25 }; int sort(const void *x, const void *y) { return (*(int*)x - *(int*)y); } void main() { clrscr(); int i; qsort(array, 10, sizeof(int), sort); for (i=0; i<10; i++) { printf("%d ", array[i]); } getch(); }

Output will be displayed as:

ARRAYSOR.EXE

3 8 25 28 30 33 36 49 80 90