How to check if array is multidimensional? (jQuery)

Question

I have two arrays of AJAX (JSON) response:

One dimension:

[["fili","Chif"],["Bart","deme"],["Bomb","Jyui"],["Joiu","FDPi"],["Doen","abcd"],["drog","MAIC"],["Jasi"
,"abcd"],["Jere","Jibi"]]

Three dimensions:

[[["5","#"],["2","N"],["L","7"],["C","8"],["F","W"],["K","T"],["Q","E"],["Z","\/"]],[["B","O"],["$","P"
],["1","Y"],["H","R"],["3","%"],["I","U"],["M","4"],["A","9"]],[["J","X"],["Bye","G"],["D","V"],["Bye"
,"6"]]]

I try to check if an array is multidimensional but does not work:

if (typeof arr[0][0] != "undefined" && arr[0][0].constructor == Array) {
     return true;
}

possible duplicate of [How to check if a multidimensional array item is set in JS?](http://stackoverflow.com/questions/16883473/how-to-check-if-a-multidimensional-array-item-is-set-in-js) — Oliver Gondža, Jun 28 '15 at 21:40
Never use `==` or `!=` in Javascript. They're totally broken... go for `===` and `!==` instead. — 6502, Jun 28 '15 at 21:57

bugwheels94 · Accepted Answer · 2015-06-29T07:35:52.550

22

You need to check the first element of Array so use

if(arr[0].constructor === Array)

DEMO

alert("[[]] returns " + ([[]].constructor === Array))

edited Jun 29 '15 at 07:35

answered Jun 28 '15 at 21:22

bugwheels94

28,872
3
36
59

It worked when i changed to if(arr[0][0].constructor == Array) Thanks! – FBN Jun 28 '15 at 21:44

score 8 · Answer 2 · answered Mar 29 '19 at 11:57

8

You can also check all elements in the array so I think it would be more right way in 2019

const is2dArray = array =>  array.every(item => Array.isArray(item));

answered Mar 29 '19 at 11:57

Stanislav Padimanskas

81
1
1

JohnP2 · Answer 3 · 2017-02-20T18:36:49.607

4

If you like my answer, please vote for the person above me, but here is the above answer reconstructed in function format:

function is2dArray(array){
    if(array[0] === undefined){
        return false;
    }else{
        return (array[0].constructor === Array);
    }
}

demo

edited Feb 20 '17 at 18:36

answered Feb 18 '17 at 16:45

JohnP2

1,731
17
15

score 1 · Answer 4 · answered Nov 30 '18 at 07:08

1

if(array[0][0] === undefined){
    return true;
}else{
    return false;
}

this one checks if the Array is a multi or just a normal array.

answered Nov 30 '18 at 07:08

Shibhe Tepa

84
4

score 0 · Answer 5 · answered Dec 10 '19 at 11:31

0

Instead of using the constructor property, you may also use instanceof:

var arr = [];
var obj = {};

(arr instanceof Object)
// -> true

(obj instanceof Object)
// -> true

(arr instanceof Array)
// -> true

(obj instanceof Array)
// -> false

answered Dec 10 '19 at 11:31

Tim

2,312
23
18

How to check if array is multidimensional? (jQuery)

5 Answers5