javascript var statement and performance

Question

Option1 : multiple var without assignment

function MyFunction() {

  var a = null;
  var b = null;
  ....
  var z = null;

  a = SomeValue;
         


        

Answer 1

Just stay away from option 1 if possible, there is no need to make two assignments.

Even variables declared inside a for loop or other compound statement/block will be available outside its containing block.

You can also do:

function MyFunction() {

  var a = SomeValue, b = SomeVavlue2;

}