Filter
JavaScript
function filter(predicate, arr) {
var acc = [];
for (let i = 0; i < arr.length; i++) {
if (predicate(arr[i], i)) {
acc.push(arr[i]);
}
}
return acc;
}
var even = (item, idx) => item % 2 == 0
console.log(filter(even, [1, 2, 3, 4, 5, 6, 7, 8, 9]))