Else statement not executed javascript

Question

Hey Guys in the below code every time the if statement is executed no matter what the condition is.

function addRow(tableID) {

            var table = document.         


        

Answer 1

At first check the null condition, this is basic law if something is present then proceed further , as in your case if element is not present it will throw undefined and nothing will work. even replace = with == in hidden part