Filter null from an array in JavaScript
Well, since all of your values are falsy, just do a !!
(cast to boolean) check:
[1,"", null, NaN, 2, undefined,4,5,6].filter(x => !!x); //returns [1, 2, 4, 5, 6]
Edit: Apparently the cast isn't needed:
document.write([1,"", null, NaN, 2, undefined,4,5,6].filter(x => x));
And the code above removes ""
, null
, undefined
and NaN
just fine.
It is a problem with NaN
, because
NaN !== NaN
read more here: Testing against NaN
.
For filtering the values, you could check for truthyness.
function bouncer(arr) {
return arr.filter(Boolean);
}
console.log(bouncer([1, "", null, NaN, 2, undefined, 4, 5, 6]));