Why does != work and just = doesn't?

Question

Here\'s my code:

  if (document.getElementById(\"hiddenButton\").style.visibility != \"visible\") {
     document.getElementById(\"hiddenButton\").style.visibili         


        

Answer 1

JS Comparison operators

==      is equal to 
===     is exactly equal to (value and type)
!=      is not equal

For example:

var x = 1;  //define and assigned and now x equal to 1
x = 3;        //now x equal to 3

if( x == 4) {
    //you won't see this alert
    alert('Hello, x is 4 now');
} else {
    //you will see this alert
    alert('Hello, x hasn not been changed and it is still ' + x.toString());
}