JavaScript Variables and Scope

js-variables-and-scope.js

v1 = 1; // Global Scope
var v2 = 2; // Variable defined with var keyword but not within a function: Global Scope
 
function f() {
    v3 = 3; // No var keyword: Global Scope
    var v4 = 4; // Local Scope only
    var v5 = v1+v2+v3; //1+2+3=6 - Local Scope only, can access v1 and v2 variables from the Global Scope
}

v1; //1 - JavaScript can access the variable as it lives in the Global Scope
v2; //2 - JavaScript can access the variable as it lives in the Global Scope
v3; //3 - JavaScript can access the variable as it lives in the Global Scope

v4; //ReferenceError: v4 is not defined (JavaScript cannot access the local scope of function f()
v5; //ReferenceError: v5 is not defined (JavaScript cannot access the local scope of function f()