CODEWITHSUNDEEP
javascriptarraysobject
TIMEX
TIMEX

Reputation: 271924

How do I determine if something is an Array or Object?

Array and object are the only inputs . Is there a simple function that can determine whether a variable is an array or object?

Upvotes: 1

Views: 212

Answers (4)

elclanrs
elclanrs

Reputation: 94101

I suspect there are many other similar answers but this is one way:

if ({}.toString.call(obj) == '[object Object]') {
  // is an object
}

if ({}.toString.call(obj) == '[object Array]') {
  // is an array
}

This can be turned into a nifty function:

function typeOf(obj) {
  return {}.toString.call(obj).match(/\w+/g)[1].toLowerCase();
}

if (typeOf(obj) == 'array') ...

This works for any type:

if (typeOf(obj) == 'date') // is a date
if (typeOf(obj) == 'number') // is a number
...

Upvotes: 3

PSL
PSL

Reputation: 123739

First check if it is an instanceof Array and then if it of object type.

if(variable instanceof Array)
{
//this is an array. This needs to the first line to be checked 
//as an array instanceof Object is also true

}
else if(variable instanceof Object)
{
//it is an object
}

Upvotes: 1

Jeff B
Jeff B

Reputation: 30099

You can use Array.isArray():

if(Array.isArray(myVar)) {
    // myVar is an array
} else {
    // myVar is not an array
}

As long as you know it will be one or the other you are set. Otherwise, combine this with typeof:

if(typeof myVar === "object") {
    if(Array.isArray(myVar)) {
        // myVar is an array
    } else {
        // myVar is a non-array object
    }
}

Upvotes: 1

Christophe
Christophe

Reputation: 28144

(variable instanceof Array) will return true for arrays.

You could also use variable.isArray(), but this is not supported by older browsers.

Upvotes: 1

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