What does if (variable) mean in C language?

Question

I'm currently preparing for gate; I have come across a question

#include<stdio.h>
main()
{
    static int var=6;
    printf("%d\t",var--);
    if(var)
        main();
}

The output is 6 5 4 3 2 1

I wanna know why it terminated after 1?

Answer 1

An if statement always tests to see if the expression inside the parentheses evaluates to true.

In this case, var is an positive integer, so it evaluates to true . Since 0 always evaluates to false , as soon as var = 0 the if statement evaluates to false and the loop exits.

Note that if(var) is not specific to C (re the question title), it applies to many languages.

Answer 2

if (var) checks whether var is not zero! If var is zero it finish.