Answers for "delete undefined from array"

remove null from array javascript

let array = [0, 1, null, 2, 3];

function removeNull(array) {
return array.filter(x => x !== null)
};

remove undefined from array javascript

var data = [42, 21, undefined, 50, 40, undefined, 9];

data = data.filter(function( element ) {
   return element !== undefined;
});