using fgets and strcmp in C [duplicate]

Answer 1

Note two things in your code:

1. fgets keeps the trailing '\n'. the associated char in fruit should be replaced with a '\0' before comparing with the string "apple".
2. strcmp return 0 when two strings are the same, so the if clause should be changed based on what you mean.(The fruit and "apple" be equivalent in the if clause)
3. Standard usage of C main function is int main(){ return 0;}

The revised code:

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

char fruit[100];

int main() {
    printf("What is your favorite fruit?\n");
    fgets (fruit, 100, stdin);
    fruit[strlen(fruit)-1] = '\0';
    if (strcmp(fruit, "apple") == 0) {
        printf("Watch out for worms!\n");
    }
    else {
        printf("You should have an apple instead.\n");
    }
    return 0;
}

Answer 2

Change the if condition to the following:

if(strcmp(fruit,"apple") == 0)

strcmp returns 0 strings if match. You should always compare the result using == operator

Answer 3

strcmp returns 0 if the inputs match, some value>0 if the left is "greater" than the right, some value<0 if the left is "lesser" than the right. So usually you want to simply test for equality with strcmp(...)==0. But there is also the clever version: !strcmp(...). Even if you don't use this style, it's useful to learn to recognize it.

And remember that fgets does not remove the newline character '\n' from the string.