Array Method Challenges

Challenge 1

Instructions:

Take the people array and create an array called youngPeople that stores objects with ONLY name and email properties of all the people that are 25 and under. The name property should have their first and last name.

const people = [
  {
    firstName: 'John',
    lastName: 'Doe',
    email: 'john@gmail.com',
    phone: '111-111-1111',
    age: 30,
  },
  {
    firstName: 'Jane',
    lastName: 'Poe',
    email: 'jane@gmail.com',
    phone: '222-222-2222',
    age: 25,
  },
  {
    firstName: 'Bob',
    lastName: 'Foe',
    email: 'bob@gmail.com',
    phone: '333-333-3333',
    age: 45,
  },
  {
    firstName: 'Sara',
    lastName: 'Soe',
    email: 'Sara@gmail.com',
    phone: '444-444-4444',
    age: 19,
  },
  {
    firstName: 'Jose',
    lastName: 'Koe',
    email: 'jose@gmail.com',
    phone: '555-555-5555',
    age: 23,
  },
];

Expected Result:

console.log(youngPeople);

[
  {name: 'Jane Poe', email:'jane@gmail.com'},
  {name: 'Sara Soe', email:'sara@gmail.com'},
  {name: 'Jose Koe', email:'jose@gmail.com'}
]

Click For Solution

const youngPeople = people
  .filter((person) => person.age <= 25)
  .map((person) => ({
    name: person.firstName + ' ' + person.lastName,
    email: person.email,
  }));

Challenge 2

Instructions:

Add all of the positive numbers in the array.

Expected Result:

const numbers = [2, -30, 50, 20, -12, -9, 7];

console.log(positiveSum); // 79

Click For Solution

const numbers = [2, -30, 50, 20, -12, -9, 7];

const positiveSum = numbers
  .filter((number) => number > 0)
  .reduce((acc, cur) => acc + cur, 0);

console.log(positiveSum);

Challenge 3

Instructions:

Create a new array called capitalizedWords with the words from the words array with the first letter of each word capitalized.

Expected Result:

const words = ['coder', 'programmer', 'developer'];

console.log(capitalizedWords); // ['Coder', 'Programmer', 'Developer']

Hint:

Remember back a few sections, we had a challenge to capitalize the first letter of a string. You are doing the same thing here, but for each word in the array.

Click For Solution

const capitalizedWords = words.map(
  (word) => word[0].toUpperCase() + word.slice(1, word.length)
);