why the answer is 0? thanks in advance

Question

var x=1;
if(x){
x=0;
}
if(x){
x=1;
}
document.write(x);

Answer 1

0 is false and any non-zero value is true.

Answer 2

var x=1; //x is now 1
if(x){ // validates condition
x=0; //now x is 0
}
if(x){ //fails condition
x=1;
}
document.write(x); //prints 0

That's it.

Answer 3

Any non-zero number is True whereas zero is False.
Since, x=1 at the first if the condition is True, and it is executed, which makes the value of x=0. Now, the second if is not executed since x becomes 0, and hence the condition is false. That is why the answer is zero.