Check if all of array items are undefined or empty string

Question

How to check if all of items are undefined or empty string ''?

var items = [variable_1, variable_2, variable_3];

Is there any nice way to do that instead of big if? Not ES6.

There's a .every() method on the Array prototype. (edited) — Pointy
– Pointy, Commented Jun 24, 2019 at 14:18
items.every(function(item) { return item === undefined || item === '' }) is ES5.1 -- or you could just check for falsey-ness (which includes null, empty strings, undefined, etc) !item — Andrew Li
– Andrew Li, Commented Jun 24, 2019 at 14:19
Actually, it's .every. .all is not standard JS, it's probably some library you've used — junvar
– junvar, Commented Jun 24, 2019 at 14:19
Use .every() or .filter() depending on what you want to do (test all values or only get the values that have some value you care about). — Charlie Schliesser
– Charlie Schliesser, Commented Jun 24, 2019 at 14:19

CD.. · Accepted Answer · 2019-06-24 14:19:48Z

3

You can use every:

The every() method tests whether all elements in the array pass the test implemented by the provided function. It returns a Boolean value.

answered Jun 24, 2019 at 14:19

CD..

74.4k25 gold badges160 silver badges170 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Alexandre Senges · Accepted Answer · 2019-06-24 14:23:20Z

0

A one liner that uses Array.prototype.some to find at least one element which is not undefined or '', if it finds one it returns true

!items.some(item => item != undefined || item != '')

answered Jun 24, 2019 at 14:23

Alexandre Senges

1,6091 gold badge15 silver badges23 bronze badges

1 Comment

Andrew Li Over a year ago

Consider using strict comparison, i.e. !==. Also, arrow functions are ES6. OP doesn't want ES6

Pointy · Accepted Answer · 2019-06-24 14:24:54Z

0

Here's another one I just thought of:

if (array.join("") === "") 
  // all undefined or ""

Note that that'll also be true if an element is null, not undefined, so it may or may not suit the OP. Advantage is that it doesn't need a callback function.

answered Jun 24, 2019 at 14:24

Pointy

415k62 gold badges600 silver badges631 bronze badges

Collectives™ on Stack Overflow

Check if all of array items are undefined or empty string

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related