In javascript how can we identify whether an object is a Hash or an Array?

Question

The output of my JSON call can either be an Array or a Hash. How do I distinguish between these two?

Answer 1

Modern browsers support the Array.isArray(obj) method.

See MDN for documentation and a polyfill.

= original answer from 2008 =

you can use the constuctor property of your output:

if(output.constructor == Array){ } else if(output.constructor == Object){ } 

Answer 2

Is object:

function isObject ( obj ) {    return obj && (typeof obj  === "object"); } 

Is array:

function isArray ( obj ) {    return isObject(obj) && (obj instanceof Array); } 

Because arrays are objects you'll want to test if a variable is an array first, and then if it is an object:

if (isArray(myObject)) {    // do stuff for arrays } else if (isObject(myObject)) {    // do stuff for objects }