Giter Club home page Giter Club logo

javascript_objects_arrays's Introduction

JavaScript Objects and Arrays

Getting Started

  1. Open your command line and navigate to your repos directory (if you do not have a repos folder, then you can use mkdir repos to create one)
  2. Use this template repository to start a new project in your repos folder: git clone <repo_name>
  3. cd repo_name to navigate into your new repo directory
  4. Start Visual Studio Code and select 'Open Folder'. Then select repo_name to open the folder in the editor (or just type code . in your terminal inside the repo directory)
  5. Follow the instructions on the README.md file to complete exercises
  6. Open the app.js file to get started

Exercise 1: The Sum of an Array

  • The Array Object in JavaScript has a built-in reduce method that iterates over each value in an array and returns a value. It is very useful when calculating sums.
  • Write a function that takes an array of numbers as a parameter and returns the sum value of each number in the array. (i.e. write a custom Array.prototype.reduce() function)
  • You can use the follow array: const numbers = [2, 22, 12, 17, 18, 39, 129];
  1. Declare a function arraySum that takes numbers as a parameter
  2. Declare a variable sum and initialize sum as 0
  3. Inside the arraySum function body, iterate over each number (value) in the numbers array using the array's forEach method
    • The array forEach method takes a callback (function) as a parameter, where you can pass in the value and index of the current array position
    • numbers.forEach((number, index) => {...});
  4. Inside the body of the forEach callback function, write code so that each number in the numbers array is added to the value of sum
  5. Below the forEach method, then return sum;
  6. Call the arraySum(numbers) method inside console.log to print out the returned sum.

Exercise 2: Favorite Book

  • Write a “Book” object. Your book object should have the book’s title, author, the number of pages, and whether or not you have read the book
  1. Declare a variable named book, and assign an object ({}) to the variable.
  2. Using dot notation:
    • assign the title of your favorite book to a property named title,
    • assign the number of pages to a property named pages,
    • and assign the number of times you've read the book to a property named readCount
  3. Using dot notation, add a method named info to the book object that returns a string that combines the title, pages, and readCount as an informational string. Ex: The Hobbit by J.R.R Tolkien, 295 pages, read 3 times.
  4. After you have added the properties and method to the object, call the book.info() method inside console.log to print out the returned string.

BONUS

javascript_objects_arrays's People

Contributors

cameronhardy9 avatar bryantellius avatar

Recommend Projects

  • React photo React

    A declarative, efficient, and flexible JavaScript library for building user interfaces.

  • Vue.js photo Vue.js

    🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.

  • Typescript photo Typescript

    TypeScript is a superset of JavaScript that compiles to clean JavaScript output.

  • TensorFlow photo TensorFlow

    An Open Source Machine Learning Framework for Everyone

  • Django photo Django

    The Web framework for perfectionists with deadlines.

  • D3 photo D3

    Bring data to life with SVG, Canvas and HTML. 📊📈🎉

Recommend Topics

  • javascript

    JavaScript (JS) is a lightweight interpreted programming language with first-class functions.

  • web

    Some thing interesting about web. New door for the world.

  • server

    A server is a program made to process requests and deliver data to clients.

  • Machine learning

    Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.

  • Game

    Some thing interesting about game, make everyone happy.

Recommend Org

  • Facebook photo Facebook

    We are working to build community through open source technology. NB: members must have two-factor auth.

  • Microsoft photo Microsoft

    Open source projects and samples from Microsoft.

  • Google photo Google

    Google ❤️ Open Source for everyone.

  • D3 photo D3

    Data-Driven Documents codes.