bsearch

Name

bsearch - binary search of a sorted array

Library

libc.lib

Synopsis

#include <stdlib.h>

void * bsearch (const void *key, const void *base, size_t nmemb, size_t size, int (*compar) (const void *, const void *));

Return values

The bsearch function returns a pointer to a matching member of the array, or a null pointer if no match is found. If two members compare as equal, which member is matched is unspecified.

Detailed description

The bsearch function searches an array of nmemb objects, the initial member of which is pointed to by base, for a member that matches the object pointed to by key. The size of each member of the array is specified by size.

The contents of the array should be in ascending sorted order according to the comparison function referenced by compar. The compar routine is expected to have two arguments which point to the key object and to an array member, in that order, and should return an integer less than, equal to, or greater than zero if the key object is found, respectively, to be less than, to match, or be greater than the array member.

Examples

#include<stdlib.h>
#include<stdio.h>
 
int search_function(const void* a,const void* b)
{
    return(*(int *)a - *(int *)b);
}
 
int main()
{
int arr[] = {3,5,7,8,10};
int key = 7;
int i = 5;
 
int *ele;
 
ele  = ( int* ) bsearch(&key, (void *)arr, i, sizeof(arr[0]), search_function);
 
if (ele != NULL)
        printf("\nelement found: %d", *ele);
else
        printf("\nelement not found");
return 0;
}

Output

element found: 7

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