JavaScript Basics Stephen Delaney sdelaney@skokielibrary.info

Review: Creating Reusable Code with Functions Creating functions Returning values from functions Variable scope

Creating a Function When you see parentheses following a name, you know you’re seeing a function No semicolon after the closing brace

Calling a Function The bottom line calls the function

Return Statements Return statements: Pass a value (only one) Exit immediately

Arguments and Parameters The argument is stored in a variable called a parameter person is the parameter "Frank" is the argument

Variable Scope Function scope vs. global scope

Variable Scope Function scope vs. global scope

isNaN()

Throwing Errors

Questions? https://teamtreehouse.com/library/using-sql-and-nodejs-with-sequelize

Review https://teamtreehouse.com/library/using-sql-and-nodejs-with-sequelize

Variables Variables must begin with a letter, $ or _ Variables are case-sensitive var person and var Person are two variables typeof

Strings Properties i.e. string.length Methods i.e. string.toUpperCase()

Concatenation

Types of Numbers Integers 10, -8, 2787382 Floating point numbers 3.14, -10.6454 Scientific notation 5.7e+4 => 57000

Shorthand Operators += -= *= /= x += y is shorthand for x = x + y

Parsing Numbers parseInt() parseInt(10.6) 10 parseFloat() parseFloat(10.6) 10.6

Terms NaN Not a Number DRY Don’t Repeat Yourself

The Math Object Math.round() Math.round(10.6)  11 Math.floor() Math.ceil() Math.ceil(10.6)  11

The Math Object Math.random() Floating number, from 0 (inclusive) to 1 (exclusive)

Comparison Operators Operator Meaning True expressions == Equality 10 == '10' === Strict equality (2 * 5) === 10 != Inequality 9 != 10 !== Strict inequality '10' !== 10 > Greater than 20 > 10 >= Greater than or equal '10' >= 10 < Less than 10 < 30 <= Less than or equal '10'<= 10

And Operator: && Condition 1 Condition 2 Result TRUE FALSE

Or Operator: || Condition 1 Condition 2 Result TRUE FALSE

Not Operator: ! Condition Result TRUE FALSE

If Statements integrated development environment

What’s next?

Next Steps jQuery jQuery is used by 71.8% of all websites. That is a JavaScript library market share of 96.4%. https://w3techs.com/technologies/overview/javascript_library/all

Next Steps AJAX Asynchronous JavaScript And XML Get data without a page refresh https://w3techs.com/technologies/overview/javascript_library/all

Next Steps MEAN stack “In the MEAN stack, we use MongoDB as our database. We write most of our code in Javascript. We rely on Node and Express.js to host our application and serve APIs/Views. We use AngularJS to render our views that are served by Express.”

Next Steps MEAN stack

Navigate to library: Sort by difficulty Select course Select JavaScript https://teamtreehouse.com/library/topic:javascript/type:course/sort:difficulty

Recommended Syllabus JavaScript Loops, Arrays and Objects JavaScript and the DOM jQuery Basics There is also a shorter one called Introduction to jQuery. AJAX Basics

Recommended Syllabus Interactive Web Pages with JavaScript Object-Oriented JavaScript Node.js Basics Build a Simple Dynamic Site with Node.js Express Basics Build a REST API With Express Mongo Basics* Angular Basics* Building a MEAN Application *Indicates a course that is not under JavaScript Application program interface (API) Representational state transfer (REST) Create, read, update, destroy (CRUD) http://softwareengineering.stackexchange.com/questions/120716/difference-between-rest-and-crud

NoSQL vs. SQL

Comparing NoSQL and SQL Are you Google? Do you know what you are building? What framework are you in?

Comparing NoSQL and SQL What is NoSQL? SQL vs. NoSQL The NoSQL Debate: Automatic vs. Manual Transmission When should I use a NoSQL database instead of a relational database? NoSQL Use Case Scenarios or WHEN to use NoSQL

Comparing NoSQL and SQL http://db-engines.com/en/ranking

ORM

ORM Object-relational Mapping Translates between you and SQL Makes life easier! MEAN stack is optimized for MongoDB (Mongoose ORM), but if you would like to use SQL: Sequelize Treehouse: Using SQL and Node.js with Sequelize Bookshelf.js

Thanks!