A program to compare two strings without using library function

C Programming Language 069

The following code shows how to write a program to compare two strings without using library function.

Program

#include <stdio.h>

void main()
{
    char str1[30], str2[30];
    int i, equal = 1, len1 = 0, len2 = 0;

    printf("Enter string 1: ");
    gets(str1);

    printf("Enter string 2: ");
    gets(str2);

    for (i = 0; str1[i] != '\0'; i++)
    {
        len1++;
    }
    for (i = 0; str2[i] != '\0'; i++)
    {
        len2++;
    }

    if (len1 != len2)
    {
        equal = 0;
    }
    else
    {
        for (i = 0; str1[i] != '\0'; i++)
        {
            if (str1[i] != str2[i])
            {
                equal = 0;
                break;
            }
        }
    }

    if (equal == 1)
    {
        printf("Both strings are equal");
    }
    else
    {
        printf("Both strings are not equal");
    }

    printf("\n");
}

Result

Enter string 1: hello
Enter string 2: hello
Both strings are equal

Enter string 1: hello
Enter string 2: world
Both strings are not equal

Enter string 1: a
Enter string 2: bc
Both strings are not equal

Last Updated on Oct 30, 2022