I need to know what the different parts of this JavaScript code means..
var x=document.getElementById("demo").value;
if(x==""||isNaN(x))
I know what the result of the code is but I need to know what things like; 'var', '(x==""||isNaN(x))
I know what the 'document.getElementById("demo").value;' means but the '(x==""||isNaN(x)) i don't understand