freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/es6/write-concise-declarative-functions-with-es6.english.md

id, title, challengeType

id	title	challengeType
587d7b8b367417b2b2512b50	Write Concise Declarative Functions with ES6	1

Description

When defining functions within objects in ES5, we have to use the keyword function as follows:

const person = {
  name: "Taylor",
  sayHello: function() {
    return `Hello! My name is ${this.name}.`;
  }
};

With ES6, You can remove the function keyword and colon altogether when defining functions in objects. Here's an example of this syntax:

const person = {
  name: "Taylor",
  sayHello() {
    return `Hello! My name is ${this.name}.`;
  }
};

Instructions

Refactor the function setGear inside the object bicycle to use the shorthand syntax described above.

Tests

tests:
  - text: Traditional function expression was not used.
    testString: getUserInput => assert(!getUserInput('index').match(/function/),'Traditional <code>function</code> expression was not used.');
  - text: <code>setGear</code> is a declarative function.
    testString: getUserInput => assert(typeof bicycle.setGear === 'function' && getUserInput('index').match(/setGear\s*\(.+\)\s*\{/), '<code>setGear</code> is a declarative function.');
  - text: <code>bicycle.setGear(48)</code> changes the <code>gear</code> value to 48.
    testString: assert((new bicycle.setGear(48)).gear === 48, '<code>bicycle.setGear(48)</code> changes the <code>gear</code> value to 48.');

Challenge Seed

// change code below this line
const bicycle = {
  gear: 2,
  setGear: function(newGear) {
    this.gear = newGear;
  }
};
// change code above this line
bicycle.setGear(3);
console.log(bicycle.gear);

Solution

const bicycle = {
  gear: 2,
  setGear(newGear) {
    this.gear = newGear;
  }
};
bicycle.setGear(3);