Can't leave loop

Question

I created small code in C to test something. I thought that if i write 0 I will receive output ABC. But I cannot leave the loop. Please help me. Thank you.

#include<stdio.h>
#include<stdlib.h>

int main()
{

int x;

while(1)
    {
    printf("Enter number\n");
    scanf("%d",&x);
    if(x=0)
        goto stop;
    }

stop:
    printf("ABC");

return 0;
}

`if(x=0)` is assigning, not comparing. Also, don't `goto stop;`... just `break;`. — indiv, Oct 31 '14 at 01:13
please don't use `goto`, you can just `break` out of the loop — Bryan Chen, Oct 31 '14 at 01:15
You should test the result of [scanf(3)](http://man7.org/linux/man-pages/man3/scanf.3.html) — Basile Starynkevitch, Oct 31 '14 at 02:14

score 3 · Accepted Answer · answered Oct 31 '14 at 01:15

3

Change the line

     if(x=0)

to

     if (x==0)

Originally you were assigning 0 to x, but you want to compare. To compare x with 0 you need to use ==

answered Oct 31 '14 at 01:15

smushi

701
6
17

1

ya might consider telling him why. – EvilTeach Oct 31 '14 at 01:17
BTW, if you enable all warnings & debug info in your compiler, you would be warned with `gcc -Wall -Wextra -g` – Basile Starynkevitch Oct 31 '14 at 02:13

score 2 · Answer 2 · answered Oct 31 '14 at 01:15

2

the code is wrong the code

if(x = 0 )

should change to

if(x == 0 )

answered Oct 31 '14 at 01:15

cijianzy

71
2
8

score 0 · Answer 3 · answered Oct 31 '14 at 02:50

As the others pointed out, a single equal sign in c is assignment, and a double equals sign tests for equality. In this case, the double equals sign is needed. So instead of if(x = 0), you want if(x == 0)
One more tip, using break is preferable to a goto statement here. Hope this helps.

Can't leave loop

3 Answers3