What is wrong here? (JAVASCRIPT)

Question

function num(a,b){
document.write(a+"is greater than"+b);
}
var x=num(18,16);

alert(x);

Answer 1

You are wrong.
Nah jk, it should be,

function num(a,b){
alert(a+"is greater than"+b);
}
num(18,16);

OR

function num(a,b){
return a+"is greater than"+b
}
var x=num(18,16);

alert(x);

Answer 2

function num(a,b)
{
if(a > b)
return document.write(a+"is greater than"+b);
else
return document.write(b+"is greater than"+a);
}

var x = num(18, 16);
alert(x);

works for any number .. greater or less than.