What is the scope of variables in JavaScript?

Question

What is the scope of variables in javascript? Do they have the same scope inside as opposed to outside a function? Or does it even matter? Also, where are the variables stored if they are defined globally?

Answer 1

The scope in Javascript is used to establish the scope for a given function. Typically there is one global scope, and every defined function has its own nested scope.

See the example below:-

• A globally-scoped variable

var a = 1;

function one() {

 alert(a); 

}

• Local scope

var a = 1;

function two(a) {

alert(a); 

} 

function three() {

var a = 3; 

alert(a);

}