What does [] mean in JavaScript?

Question

In the following javascript code there is [] being assigned as the value of a variable, what does it mean?

var openTollDebug = []; 

Answer 1

it is an array literal. It is not quite the same as declaring new Array() - the Array object can be overwritten in JavaScript, but the array literal can't. Here's an example to demonstrate

// let's overwrite the Array object Array = function(id) {  this.id = id; }  var a = new Array(1); var b = [];  console.log(a.hasOwnProperty("id")); // true console.log(b.hasOwnProperty("id")); // false  console.log(a.push); // false, push doesn't exist on a console.log(b.push); // true,  but it does on b  b.push(2); console.log(b); // outputs [2] 

Answer 2

It means an array.

var openTollDebug = []; 

declares the openTollDebug variable and initializes it to an empty array. To put elements into the array you could do the following:

var stringArray = ['element1', 'element2', 'element3']; alert(stringArray[1]); // displays 'element2' var numberArray = [1, 2, 3, 4]; alert(numberArray[2]); // displays 3 var objectArray = [{ name: 'john' }, { name: 'peter' }, { name: 'tom' }]; alert(objectArray[1].name); // displays 'peter'