C library function - qsort()
Description
The C library function void qsort(void *base, size_t nitems, size_t size, int (*compar)(const void *, const void*)) sorts an array.
Declaration
Following is the declaration for qsort() function.
void qsort(void *base, size_t nitems, size_t size, int (*compar)(const void *, const void*))
Parameters
base − This is the pointer to the first element of the array to be sorted.
nitems − This is the number of elements in the array pointed by base.
size − This is the size in bytes of each element in the array.
compar − This is the function that compares two elements.
Return Value
This function does not return any value.
Example
The following example shows the usage of qsort() function.
#include <stdio.h>
#include <stdlib.h>
int values[] = { 88, 56, 100, 2, 25 };
int cmpfunc (const void * a, const void * b) {
return ( *(int*)a - *(int*)b );
}
int main () {
int n;
printf("Before sorting the list is: \n");
for( n = 0 ; n < 5; n++ ) {
printf("%d ", values[n]);
}
qsort(values, 5, sizeof(int), cmpfunc);
printf("\nAfter sorting the list is: \n");
for( n = 0 ; n < 5; n++ ) {
printf("%d ", values[n]);
}
return(0);
}
Let us compile and run the above program that will produce the following result −
Before sorting the list is:
88 56 100 2 25
After sorting the list is:
2 25 56 88 100
stdlib_h.htm
