What are the best practices to follow when declaring an array in Javascript?

Question

When I need to declare a new array I use this notation

var arr = new Array();

But when testing online, for example on jsbin, a warning sign

Answer 1

• var arr=[] uses the array/object literal
• var arr = new Array() use the array/object constructor

The speediest way to define an array or object is literal way, because you don't need to call the constructor

var arr1 = new Array(1, 2, 3, 4);
var arr2 = [1, 2, 3, 4];

alert(arr1[0]); // 1
alert(arr2[0]); // 1

var arr3 = new Array(200);
var arr4 = [200];

alert(arr3[0]); // 'undefined'
alert(arr4[0]); // 200