Declaring a Javascript variable twice in same scope - Is it an issue?

Question

Would the following code cause any issues?:

var a = 1;
var a = 2;

My understanding is that javascript variables are declared at the start o

Answer 1

Such a duplicate variable declaration will not cause any problems thanks to javascript's variable hoisting feature. so in your DOM wherever you have declared variables but assigned (or) not assigned, they will be placed at the top during compilation.

Example:
    var foo='hai!';
    bar='welcome!';
    var bar;

You may expect above code snippet should throw "unidentified" error but still javascript manages it by placing the bar variable's declaration at the top. So even before variable declaration its value can be assigned as opposed to other languages.

Hope this helps you to some extent