JS Methods

Question 1

filter

Answer 1

The filter function, rather than deleting elements from the existing army, builds up a new array with only the elements that pas the test. This function is pure. It does not modify the array it is given. (standard method on arrays).

Internal workings:

function filter(array, test) {
     var passed = [];
     for (var i = 0; i  [{name: "Carolus Haverbeke", ...}]

Question 2

map

Answer 2

similar to filter (page 95 in E.JS)

internal workings:

function map(array, transform) {
     var mapped = [];
     for (var i= 0; i

Question 3

reduce

Answer 3

similar to filter (page 96 in E.JS)

function reduce (array, combine, start) {
     var current = start;
     for (var i = 0; i

Question 4

forEach

Answer 4

function forEach(array, action) {
     for (var i = 0; i

Question 5

.isEqual(expected value)

Answer 5

Resolves to true