JavaScript shorthands

by yong

JavaScript

var a = (b > 10) ? true : false;

var a = (b > 10);

// Check multiple values
if("b" === "a" || "b" || "c") { }

// Create array
var arr = ['a','b','c'];

// Create object
var obj = { x: 3, y: 5 };

// Key value dictionary
var dictionary = { 'name': 'Chuck Norris', 'age': 'Unknown', 'power': 'Unlimited' };
alert(dictionary['name']);

// Check undefined with default value
var x = someVariable || 10;

// Reversed for-loop
var i = array.length;
while (i--) {
    // do something
}

// Shorthand shorthands :)

//Check if variable is null, empty or undefined
//'', 0, null, undefined = false
var s = '';
if(s) {
    //false   
}

// Shorthand if statement
//1===1&&alert('true');
//1===1?alert("true"):alert("false")

// Short for false
//alert(!1 == false);