Is it wrong to declare a variable inside an if statement in Javascript?

Question

I have a Sublimelinter installed in Sublime Text 2 and it\'s great. However it doesn\'t like the following code:

if(condition){
    var result = 1;
}else{
           


        

Answer 1

JavaScript does not have block scope. Variables are scoped to the function they are defined in, meaning that when you declare a variable inside of an if block, it is "hoisted" to the top of the function.

Since the variable is technically defined at the top of the function anyway, it is considered a best practice to move variable declarations to the top of the function so that the intent of the code is clear.

I'd say your code isn't "wrong" but it is misleading to people reading the code who aren't familiar with how scope works in JavaScript. I would definitely opt for the second version, because it actually reflects how the code is executed.

Here's a good article explaining variable hoisting.