Sample of the Array filter( ) method.

array-filter.js

//Array filter() method

let numbers = [23, 45, 14, 66, 94, 33, 4, 9];
let breakPoint = 30;

let smallNumbers = numbers.filter(function(num){
    return num < breakPoint;
});

let bigNumbers = numbers.filter(checkBig);

function checkBig(num){
    return num > breakPoint;
}

let oddNumbers = numbers.filter(function(num){
    //let remainder = num % 2;
    //0, 1, 10, 11, 100, 101, 110, 111, 1000
    //0, 1, 2,  3,   4,   5,   6,   7,   8
    return num & 1;
});

console.log('\nSmaller than 30:', smallNumbers);
console.log('\n Larger than 30:', bigNumbers);
console.log('\n Odd numbers:', oddNumbers);