findGirls.js

const people = [{
		id: 1,
		age: 18,
		weight: '70kg',
		followers: 200,
		height: '160mm',
		firstName: 'Loi',
		lastName: 'Tran',
		friendsCount: 100,
		nationality: 'USA',
		favoriteColor: 'red',
		friendsList: [2, 3],
		company: 'CoderSchool',
		occupation: 'Instructor',
		birthday: new Date(1987, 1, 8),
		favoriteSinger: 'Taylor Swift',
		favoriteQuote: 'If it was easy everyone would do it',
		gender: 'm'
	},
	{
		id: 2,
		age: 19,
		followers: 300,
		weight: '50kg',
		height: '180mm',
		lastName: 'Lee',
		friendsCount: 200,
		nationality: 'USA',
		friendsList: [1],
		firstName: 'Charles',
		favoriteColor: 'red',
		company: 'CoderSchool',
		occupation: 'Instructor',
		birthday: new Date(1988, 2, 19),
		favoriteSinger: 'Justin Bieber',
		favoriteQuote: 'What one programmer can in a month, two programs can do in two',
		gender: 'm'
	},
	{
		id: 3,
		age: 23,
		followers: 600,
		weight: '54kg',
		height: '175mm',
		firstName: 'Hoa',
		lastName: 'Huynh',
		nationality: 'VN',
		friendsCount: 500,
		occupation: 'Student',
		company: 'CoderSchool',
		favoriteColor: 'black',
		favoriteSinger: 'John Mayer',
		birthday: new Date(2000, 10, 24),
		friendsList: [1, 2, 4, 5, 6, 7, 8],
		favoriteQuote: 'Make the world want to fork you on github',
		gender: 'm'
	},
	{
		id: 4,
		age: 18,
		followers: 100,
		height: '171mm',
		weight: '58kg',
		firstName: 'Anh',
		friendsCount: 900,
		lastName: 'Nguyen',
		occupation: 'Student',
		company: 'CoderSchool',
		favoriteSinger: 'None',
		favoriteColor: 'black',
		nationality: 'Vietnamese',
		birthday: new Date(1995, 7, 22),
		friendsList: [1, 2, 3, 5, 6, 7, 8],
		favoriteQuote: "You dont have to be great to start, but you have to start to be great. - Zig Ziglar",
		gender: 'f'
	},
	{
		id: 5,
		age: 26,
		followers: 900,
		weight: '59kg',
		height: '173mm',
		friendsCount: 200,
		lastName: 'Nguyen',
		firstName: 'Philip',
		favoriteColor: 'red',
		company: 'CoderSchool',
		nationality: 'Murrican',
		occupation: 'novice programmer',
		birthday: new Date(1970, 6, 11),
		favoriteSinger: 'Action Bronson',
		friendsList: [1, 2, 3, 4, 6, 7, 8],
		favoriteQuote: 'Im here to learn coding and chew bubblegum, and Im fresh outta bubblegum.',
		gender: 'm'
	},
	{
		id: 6,
		age: 26,
		followers: 700,
		weight: '61kg',
		height: '174mm',
		firstName: 'Huy',
		nationality: 'VN',
		friendsCount: 500,
		lastName: 'Nguyen',
		favoriteColor: 'Blue',
		occupation: 'Student',
		company: 'CoderSchool',
		favoriteSinger: 'Maroon5',
		birthday: new Date(1997, 12, 25),
		friendsList: [1, 2, 4, 5, 7, 8],
		favoriteQuote: "You only live once, but if you do it right, once is enough",
		gender: 'm'
	},
	{
		id: 7,
		age: 25,
		weight: '54kg',
		followers: 300,
		height: '150mm',
		nationality: 'VN',
		friendsCount: 400,
		firstName: 'Hieu',
		lastName: 'Nguyen',
		favoriteColor: 'blue',
		company: 'CoderSchool',
		occupation: 'Code learner',
		favoriteSinger: 'Leona Lewis',
		birthday: new Date(1997, 4, 27),
		friendsList: [1, 2, 3, 5, 6, 8],
		favoriteQuote: "I meant, said Ipslore bitterly, what is there in this world that truly makes living worthwhile? Death thought about it. ᴄᴀᴛs, he said eventually. ᴄᴀᴛs ᴀʀᴇ ɴɪᴄᴇ.",
		gender: 'm'
	},
	{
		id: 8,
		age: 15,
		followers: 300,
		weight: '58kg',
		height: '159mm',
		nationality: 'VN',
		friendsCount: 600,
		firstName: 'Henry',
		lastName: 'Nguyen',
		occupation: 'student',
		company: 'CoderSchool',
		favoriteSinger: 'VyVy',
		favoriteColor: 'white',
		birthday: new Date(1991, 2, 25),
		favoriteQuote: 'Mind over mater',
		friendsList: [1, 2, 3, 5, 6, 7],
		gender: 'm'
	},
	{
		id: 9,
		age: 18,
		weight: '50kg',
		followers: 600,
		height: '145mm',
		firstName: 'Diep',
		lastName: 'Tran',
		friendsCount: 700,
		nationality: 'Rung',
		favoriteColor: 'red',
		friendsList: [1, 2, 3],
		company: 'Vexere',
		occupation: 'HR Director',
		birthday: new Date(1991, 5, 8),
		favoriteSinger: 'Whitney Houston',
		favoriteQuote: 'Do unto others what you would have them do to you',
		gender: 'f'
	},
	{
		id: 9,
		age: 21,
		weight: '49kg',
		followers: 900,
		height: '170',
		firstName: 'Van',
		lastName: 'Nguyen',
		friendsCount: 700,
		nationality: 'VN',
		favoriteColor: 'pink',
		friendsList: [1, 2, 3],
		company: 'Eddie Bauer',
		occupation: 'Production Manager',
		birthday: new Date(1993, 5, 8),
		favoriteSinger: 'Whitney Houston',
		favoriteQuote: 'Tell me how you feel',
		gender: 'f'
	},
]

// 1.
function findGirls(persons) {
	const girls = []

	for (let i = 0; i < persons.length; i++) {
		if (persons[i].gender === 'f') {
			girls.push(persons[i])
		}
	}

	return girls
}

// 2. 
function findGirls(persons) {
	const girls = []
	persons.map((person) => {
		if (person.gender === 'f') {
			girls.push(person)
		}
	})

	return girls
}

// 3.
function findGirls(persons) {
	const girls = []

	persons.map(person => {
		if (person.gender === 'f') {
			girls.push(person)
		}
	})

	return girls
}

// 4. 
function findGirls(persons) {
	const girls = []

	persons.map(person => {
		if (person.gender === 'f') girls.push(person)
	})

	return girls
}

// 5. 
function findGirls(persons) {
	const girls = []

	persons.map(person => {
		person.gender === 'f' ? girls.push(person) : null 
	})

	return girls
}

// 6. 
function findGirls(persons) {
	return persons.filter(person => person.gender === 'f')
}

// 7. 
function findGirls(persons) {
	return persons.filter(({ gender }) => gender === 'f')
}

// 8. 
const findGirls = (persons) => {
	return persons.filter(({ gender }) => gender === 'f')
}

// 9. 
const findGirls = (persons) => persons.filter(({ gender }) => gender === 'f')

// 10. 
const findGirls = persons => persons.filter(({ gender }) => gender === 'f')

console.log(findGirls(people))