Question

I am trying to write a program which will output same printf if any one of the string match. I tried following but it doesn’t working for me. Here I did compare first string or second string, if any one is same then it should print the statement listed in printf.

#include <stdio.h>
#include <string.h>

int main (){

    char string1[10];
    char string2[10];

    printf("Enter the first string: ");
    scanf ("%s", string1);

    printf("Enter the second string: ");
    scanf ("%s", string2);

    if ((strcmp(string1, "test1") == 0) || (strcmp (string2, "test2") ==0))

        printf ("Both strings are same\n");

    else printf("You didnt enter any matching \n");

}

What am I missing here?

Answer 1

Your print statement doesn’t match the first sentence of your post or your if expression. If you want to test that both are equal, you should be using && rather than ||. If you want to test if either of the strings matches your test strings, your program is fine. You must have a problem with a different part of your code. Here’s an example program to prove it for you:

#include <stdio.h>
#include <string.h>
int main(int argc, char **argv)
{
    char *string1 = argv[1];
    char *string2 = argv[2];

    if ((strcmp(string1, "test1") == 0) || (strcmp (string2, "test2") ==0)) 
         printf ("At least one string matched\n");

    return 0;
}

And output:

$ ./example test1 bad
At least one string matched
$ ./example bad test2
At least one string matched
$ ./example bad bad
$ ./example test1 test2
At least one string matched

Edit: It occurs to me on further reading that you actually might want to be testing to see if exactly one of them matches. In that case, you’ll need a different expression in your if. Maybe something like:

int string1Matches = (strcmp(string1, "test1") == 0);
int string2Matches = (strcmp(string2, "test2") == 0);

if ((string1Matches && !string2Matches) || (!string1Matches && string2Matches))
    printf("Exactly one string matches (not both!)\n");

Edit again:

Your new program seems to work fine – what is your problem? Example output:

$ ./example 
Enter the first string: test1
Enter the second string: bad
Both strings are same
$ ./example 
Enter the first string: bad  
Enter the second string: test2
Both strings are same
$ ./example 
Enter the first string: test1
Enter the second string: test2
Both strings are same
$ ./example 
Enter the first string: bad
Enter the second string: bad
You didnt enter any matching