Remove empty elements from an array in Javascript

Question

How do I remove empty elements from an array in JavaScript?

Is there a straightforward way, or do I need to loop through it and remove them manually?

Answer 1

Simple ways:

var arr = [1,2,,3,,-3,null,,0,,undefined,4,,4,,5,,6,,,,];   arr.filter(n => n) // [1, 2, 3, -3, 4, 4, 5, 6]  arr.filter(Number)  // [1, 2, 3, -3, 4, 4, 5, 6]  arr.filter(Boolean)  // [1, 2, 3, -3, 4, 4, 5, 6] 

or - (only for single array items of type "text")

['','1','2',3,,'4',,undefined,,,'5'].join('').split('');  // output:  ["1","2","3","4","5"] 

or - Classic way: simple iteration

var arr = [1,2,null, undefined,3,,3,,,0,,,[],,{},,5,,6,,,,],     len = arr.length, i;  for(i = 0; i < len; i++ )     arr[i] && arr.push(arr[i]);  // copy non-empty values to the end of the array  arr.splice(0 , len);  // cut the array and leave only the non-empty values  arr // [1,2,3,3,[],Object{},5,6] 

via jQuery:

var arr = [1,2,,3,,3,,,0,,,4,,4,,5,,6,,,,];  arr = $.grep(arr,function(n){ return n == 0 || n });  arr // [1, 2, 3, 3, 0, 4, 4, 5, 6] 

UPDATE - just another fast, cool way (using ES6):

var arr = [1,2,null, undefined,3,,3,,,0,,,4,,4,,5,,6,,,,],      temp = [];  for(let i of arr)     i && temp.push(i); // copy each non-empty value to the 'temp' array  arr = temp;  arr // [1, 2, 3, 3, 4, 4, 5, 6] 

Remove empty values

['foo', '',,,'',,null, ' ', 3, true, [], [1], {}, undefined, ()=>{}].filter(String)  // ["foo", null, " ", 3, true, [1], Object {}, undefined, ()=>{}]