Question

My .c programme gives an object a ‘name’ when its created. I need to be able to excute different tasks depending on that name. I very new to this and have tried a couple of ways with no success. Here is what I had come up with..

if (name ==  "james"){

    //Do a bunch of stuff
    } 
if (name ==  "tom"){

    //Do a bunch of stuff
    } 

This was not successful. Is there a way so that if the ‘name’ is one thing it wont execute the others?

Thankyou so much for any help

Answer 1

In C, a string is defined as a sequence of characters which are terminated with \0. A string constant is normally represented within `”, for example, char a[10] = “hello”.

In order to compare two strings, you can use library functions like strcmp() which is available in string.h. Do man strcmp to read more about this function.

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

int main()
{
        char name[] = "tom";

        if (strcmp(name, "tom") == 0) {
            printf("name is tom! \n");
        } else if (strcmp(name, "bob") == 0) {
            printf("name is bob! \n");
        } else {
            printf("who is this?! \n");
        }

        return 0;
}

The strcmp could have been implemented in the following ways (array and pointer versions for your reference)

int strcmp1(char a[], char b[])
{
        int i=0;
        while (a[i] == b[i]) {
                if (a[i] == '\0')
                        return 0;
                i++;
        }

        return a[i]-b[i];
}

int strcmp2(char *a, char *b)
{
        while (*a == *b) {
                if (*a == '\0')
                        return 0;
                a++; b++;
        }
        return *a-*b;
}