Array.sort().filter(...) with zero in Javascript

Question

Why 0 is not returned by the following filter ?

[0, 5, 4].sort().filter(function(i){return i}) // returns : [4, 5]

Answer 1

0 is considered a falsy value.

Your filter function is essentially returning false for 0 and filtering it from the array.

Check this out for a deeper look.

Answer 2

.filter() function by default excludes falsy items from filtered output.

// ----- falsy items in JS --------
false 
null 
undefined
0 
NaN
'' //Empty string

Solution :

If you still want to keep them, just remember this short tip :

---

Return true to keep the element, false otherwise.

Example :

[0, 5, 4].sort().filter(function(i){
return true // returning true to keep i element
});