var-js.md

VAR

Scope essentially means where these variables are available for use. var declarations are globally scoped or function/locally scoped.

• Ex1

var greeter = "hey hi";

if (1) {
    var hello = "hello";
    console.log(hello);
    console.log(greeter);
}

• Ex2

var tester = "hey hi";

if (1) {
    var hello = "hello";
}
console.log(hello);
console.log(tester);

var is function scoped when it is declared within a function. This means that it is available and can be accessed only within that function.

var tester = "hey hi";

function sayHello() {
    var hello = "hello";
}
console.log(hello);
console.log(tester);

• Ex3 : can be re-declared and updated

var greeter = "hey hi";
var greeter = "say Hello instead";

- Question?

var greeter = "hey hi";

if (1) {
    var greeter = "hello";
}
console.log(greeter);

var greeter = "hey hi";

if (1) {
    greeter = "hello";
}
console.log(greeter);

Problem with var

    var greeter = "hey hi";
    var times = 4;

    if (times > 3) {
        var greeter = "say Hello instead"; 
    }
    
    console.log(greeter) // "say Hello instead"