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

id	title	challengeType	forumTopicId	dashedName
587d7b8b367417b2b2512b50	Write Concise Declarative Functions with ES6	1	301224	write-concise-declarative-functions-with-es6

--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.

--hints--

Traditional function expression should not be used.

(getUserInput) => assert(!__helpers.removeJSComments(code).match(/function/));

setGear should be a declarative function.

assert(
  typeof bicycle.setGear === 'function' && code.match(/setGear\s*\(.+\)\s*\{/)
);

bicycle.setGear(48) should change the gear value to 48.

assert(new bicycle.setGear(48).gear === 48);

--seed--

--seed-contents--

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

--solutions--

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