CODEWITHSUNDEEP
javascriptarraysnode.js
mre12345
mre12345

Reputation: 1127

Check if an array contains something other than null in javascript?

I have an array that will most likely always look like: 

[null, null, null, null, null]

sometimes this array might change to something like: 

["helloworld", null, null, null, null]

I know I could use a for loop for this but is there a way to use indexOf to check if something in an array that is not equal to null.

I am looking for something like: 

var index = indexof(!null);

Upvotes: 22

Views: 43482

Answers (5)

Tobias Feil
Tobias Feil

Reputation: 2696

If you just wanna check if there is any non-falsy value in the array, do

arr.some(el => !!el)

Upvotes: 2

Andy
Andy

Reputation: 63514

Use some which returns a boolean:

const arr = [null, 2, null, null];
const arr2 = [null, null, null, null];

function otherThanNull(arr) {
  return arr.some(el => el !== null);
}

console.log(otherThanNull(arr));
console.log(otherThanNull(arr2));

Upvotes: 48

Paul Roub
Paul Roub

Reputation: 36438

In recent versions of Chrome, Safari, and Firefox (and future versions of other browsers), you can use findIndex() to find the index of the first non-null element.

var arr = [null, null, "not null", null];

var first = arr.findIndex( 
              function(el) { 
                return (el !== null);
              }
            );

console.log(first);

(for other browsers, there's a polyfill for findIndex())

Upvotes: 4

Shakawkaw
Shakawkaw

Reputation: 339

This does the work

var array = ['hello',null,null];
var array2 = [null,null,null];

$.each(array, function(i, v){ 
    if(!(v == null)) alert('Contains data');
})

Upvotes: 0

TbWill4321
TbWill4321

Reputation: 8666

You can use Array.prototype.some to check if there are any elements matching a function:

var array = [null, null, 2, null];
var hasValue = array.some(function(value) {
    return value !== null;
});
document.write('Has Value? ' + hasValue);

If you want the first index of a non-null element, you'll have to get a bit trickier. First, map each element to true / false, then get the indexOf true:

var array = [null, null, 2, null, 3];
var index = array
    .map(function(value) { return value !== null })
    .indexOf(true);
document.write('Non-Null Index Is: ' + index);

Upvotes: 2

Related Questions