Why does my if statement work, but my else doesn't?

Question

Sorry if this has been asked before or is a stupid question, but I'm new to both the site and C. So, when I run this code, when I type an answer, any answer, be it right or wrong, it says what it's supposed to say when for the if statement.

Here's the code:

#include <stdio.h>
int main()
{
    int x;
    printf("1+1=");
    scanf("%d", &x);
    if("x==2"){
        printf("Watch out, we got a genius over here!");
    }
    else {
        printf("I don't even know what to say to this...");
    }
    return 0;
}

"Watch out, we got a genius over here!" - a rather unfortunate output statement. — Mitch Wheat, Oct 18 '13 at 02:37
Welcome to Stack Overflow. Please read the [About] page soon. The `if` condition as written tests whether the pointer to the string `"x==2"` is a null pointer, and it isn't, so the `if` always evaluates to true. Hence, as everyone else said, you need to remove the quotes around `x == 2`. Also, it is a good idea to print a newline at the end of each line of output. — Jonathan Leffler, Oct 18 '13 at 02:38

score 10 · Accepted Answer · answered Oct 18 '13 at 02:35

10

you need

if(x==2)

without the quotes

answered Oct 18 '13 at 02:35

Keith Nicholas

43,549
15
93
156

1

And perhaps with more breathing room: `if (x == 2) {`. White space is your friend. – Ates Goral Oct 18 '13 at 02:50

score 3 · Answer 2 · answered Oct 18 '13 at 02:37

3

try this

#include <stdio.h>
int main()
{
int x;
printf("1+1=");
scanf("%d", &x);
if(x==2){
    printf("Watch out, we got a genius over here!");
}
else {
    printf("I don't even know what to say to this...");
}
return 0;
}

answered Oct 18 '13 at 02:37

Baahubali

4,604
6
33
72

score 3 · Answer 3 · answered Oct 18 '13 at 02:37

try

#include <stdio.h>
int main()
{
    int x;
    printf("1+1=");
    scanf("%d", &x);
    //modify this line if("x==2"){
    if(x==2){
        printf("Watch out, we got a genius over here!");
    }
    else {
        printf("I don't even know what to say to this...");
    }
    return 0;
}

phuclv · Answer 4 · 2019-09-19T01:55:52.127

1

"x==2" is a string literal of type const char* that lies in memory and has an address. Addresses to real objects in C are never 0^§ so the expression is always true and the else branch will never be taken

^§Although some architecture (most notably embedded systems) may have a non-zero bit pattern for NULL pointer, but C requires them to compare equal to zero constant. See When was the NULL macro not 0?

edited Sep 19 '19 at 01:55

answered Oct 18 '13 at 03:02

phuclv

37,963
15
156
475

Why does my if statement work, but my else doesn't?

4 Answers4