Heggy Castaneda
Aug 4, 2017 · 2 min read

Falsy Bouncer

Remove all falsy values from an array.

Falsy values in JavaScript are false, null, 0, "", undefined, and NaN.

Here are some helpful links:

First approach using !!:

function bouncer(arr){
// filter function returns new filtered array
return arr.filter(function(el){
// filters in only elements that are truthy
return !!(el);
bouncer([7, "ate", "", false, 9]);

Option 2) Longer with using Boolean

function bouncer(arr) {
// temp holding pot where filtered array will reside
var result = [];
// result gets new filtered array with the elements
// that pass the test Boolean(element)
// pass element to get access to the original array
result = arr.filter(function(element){
// only element in orig. arr that pass truthy test
// will be push into result arr
return Boolean(element);
return result;

Lastly, FCC official solution.

function bouncer (arr) {
// pass in Boolean funtion as callback into filter
// each element goes through Boolean function.
// elements that pass Boolean test (truthy)
// gets returned.
return arr.filter(Boolean);
bouncer([7, "ate", "", false, 9]);

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