Filter an array of objects and return a filtered array using pure Javascript?

Question

I'm working on a coding problem for university and can't figure this out.

How can I get a new array from the above array with only applicants that have JavaScript listed as a skill using builtin methods only?

The array looks like this:

const NewApplicants = [
    { name: "Jimmy", skills: ["Docker", "JavaScript", "Ruby"] },
    { name: "Dave", skills: ["AWS", "Python"] },
    { name: "Frankie", skills: ["Azure", "JavaScript"] },
    { name: "Liam", skills: ["Java", "JavaScript"] },
    { name: "Fred", skills: ["JavaScript", "AWS"] },
    { name: "Sara", skills: ["PHP", "AWS"] },
    { name: "Matt", skills: [".Net", "PHP", "Docker"] },
];

... and the new array should look like this:

const NewJavaScriptApplicants = [
    { name: "Jimmy", skills: ["Docker", "JavaScript", "Ruby"] },
    { name: "Frankie", skills: ["Azure", "JavaScript"] },
    { name: "Liam", skills: ["Java", "JavaScript"] },
    { name: "Fred", skills: ["JavaScript", "AWS"] },
];

Answer 1

Use Array#filter and Array#includes like so:

const NewApplicants = [
    { name: "Jimmy", skills: ["Docker", "JavaScript", "Ruby"] },
    { name: "Dave", skills: ["AWS", "Python"] },
    { name: "Frankie", skills: ["Azure", "JavaScript"] },
    { name: "Liam", skills: ["Java", "JavaScript"] },
    { name: "Fred", skills: ["JavaScript", "AWS"] },
    { name: "Sara", skills: ["PHP", "AWS"] },
    { name: "Matt", skills: [".Net", "PHP", "Docker"] },
];

const JavaScriptApplicants = NewApplicants.filter(e => e.skills.includes("JavaScript"));

console.log(JavaScriptApplicants)

The filter() method creates a new array with all elements that pass the test implemented by the provided function.
_{- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter}

The includes() method determines whether an array includes a certain element, returning true or false as appropriate.
_{- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes}