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JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Accessing Items in an Array

Hara Gopal K
PLUS
Hara Gopal K
Courses Plus Student 10,027 Points
Posted by Hara Gopal K
Hara Gopal K
Courses Plus Student 10,027 Points

properties and methods in javascript

i was wondering if there are dir() and type() methods [like in python] in JavaScript to see all the available properties and methods or type of a JavaScript object/array

1 Answer

jeffrey bachynski
jeffrey bachynski
5,179 Points
jeffrey bachynski
jeffrey bachynski
5,179 Points

You can try typing in console.dir([1,2,3]) and open what shows up. (You can even just copy that and paste it into the console.) It is a similar result as console.log([1,2,3]).

In Chrome it should show up something like Array(3) with an arrow. If you press that arrow, you should see the contents of the array and at the bottom proto:Array(0). Pressing the arrow by that, you will get a list of prototype methods available in the prototype chain.

There is a typeof method as well, eg. typeof ([1,2,3]) but that returns object and typeof(Array) returns function in these cases.

Maybe this is what you are looking for, try running 

Object.getOwnPropertyNames(Array)

that should show the property names/methods that belong directly to arrays.

Or 

Object.getOwnPropertyNames(Array.prototype)

to get the prototype chain as well.

Hopefully that helps. Let me know if that is what you were looking for or if you had any issues executing the code.