Remove null values from array using Array.indexOf?

Question

I'm trying to find if there's a null value in my array without using for loops, mainly something similar to Array.indexOf. Undefined is NOT a string, it's a null value that comes up as undefined when I use console.log(ARRPREFIX)

var arr = ["**", undefined, null];
if (arr.indexOf(null) > -1) {
 console.log("Should be null");
 arr.splice(arr.indexOf(null), 1);
}

Above is my code, however it doesn't detect the undefined value, I also tried putting in "undefined" instead but that doesn't work.

• str: null ≠ undefined ≠ "undefined"
• Jamiec: You dont have an "undefined value", you have a string which so happens to have the characters undefined. It's as far from undefined as undefined can be
• Mad_ Questionnaire: undefined is not the actual string undefined, it's a null value that comes up as undefined when I use console.log(ARRPREFIX) to print the array.
• abhishekkannojia: Just use arr.filter(Boolean) It should remove falsy values

Answer 1

You can use filter to filter out falsy values (null, undefined, etc):

var array = [2, 3, null, 4, undefined, 5];
array = array.filter(Boolean);
console.log(array);

• abhishekkannojia: what about undefined ?
• Alberto Trindade Tavares: See my edited answer. Just fixed to handle undefined also
• Jamiec: And did you notice the undefined is not actually undefined
• Alberto Trindade Tavares: I considered undefined, and not "undefined". If you want to filter out the string "undefined", it is just a matter of adjusting the filter
• abhishekkannojia: You can shorten it removing inner function to filter: array.filter(Boolean)

Answer 2

I think those javascript array functions use loops on background anyway.

• Mad_ Questionnaire: The point is I don't want to loop through my entire array and delete null/undefined values, since overtime it will get bigger so for loops just won't do.
• azurinko: Those functions are going to be executed anyway, how do you thing array functions work? You can't get value of it without looping trought array. Index of is going to do that anyway...