practice_16

let arr = [0, 1, 2];

let even = arr.map(function(x) { return 2 * x; });
let odd = arr.map(function(x) { return 2 * x + 1; });

console.log(even);
console.log(odd);

let small = even.concat(odd).filter(function(x) {
    return x < 3;
});

console.log(small);

small.filter(function(x) {return x === 0; });
console.log(small);

small.forEach(function(x, i){
    console.log('arr[' + i + ']=' + x);
});