CODEWITHSUNDEEP
cstring
Kyle Orton
Kyle Orton

Reputation: 71

comparing length of strings C

I'm having trouble with comparing strings in C. Firstly, I need to find the length of each string from command-line arguments, and then compare them as well as printing the biggest one.

So far, it's just printing the length of each typed string. I need to compare them according to length, not alphabetic order.

I don't understand why is it now working and what I should do fix it? Thank you!

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

int main(int argc, char *argv[])
{
    int i, length;

    for(i = 0; i<argc; i++)
    {
        length = strlen(argv[i]);
        printf("%s %d\n", argv[i], length);

        if(strlen(argv[i]) < strlen(argv[i+1]))
        {
            printf("%s is the biggest \n", argv[i+1]);
        }
        else
        {
            printf("%s is the biggest \n", argv[i]);
        }
    }
    return 0;
}

Upvotes: 3

Views: 10755

Answers (3)

Aftnix
Aftnix

Reputation: 4599

This will not segfault ...

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

int main(int argc, char *argv[])
{
    int i, length;

    for(i = 0; i<argc - 1; i++)
    {
       length = strlen(argv[i]);
       printf("%s %d\n", argv[i], length);

    if(strlen(argv[i]) < strlen(argv[i+1]))
    {
       printf("%s is the biggest \n", argv[i+1]);
    }
    else
    {
       printf("%s is the biggest \n", argv[i]);
    }
   }
 return 0;
 }

Upvotes: 0

houbysoft
houbysoft

Reputation: 33430

There are a few problems with your code.

First of all, argv[i+1] is an illegal operation if you're doing i < argc in the for. You need to change i < argc to i < argc - 1 in the for.

Secondly, you are probably not comparing the strings you want. argv[0] is the string representing the path of your program; the first argument passed to your program is argv[1]. Therefore, you need to change the i = 0 in the for to i = 1.

Finally, if you only want the biggest string, you should not do any printing in the for loop. Rather, you should create two variables like max_length and max_length_idx where you would store the length and index of the largest string found so far. Then, after the for loop, your program would print out the string argv[max_length_idx].

Upvotes: 8

Adam Sznajder
Adam Sznajder

Reputation: 9216

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

int main(int argc, char *argv[])
{
   int i, max_length, max_index;

   max_index = 0;
   max_length = strlen(argv[0]);

   for(i = 1; i < argc; i++)
   {
        if(strlen(argv[i]) > max_length)
        {   
            max_length = strlen(argv[i]);
            max_index = i;
        }
    }

   printf("The longest is: %s with length equal: %d\n", argv[max_index], max_length);

   return 0;
}

Upvotes: 4

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