freeCodeCamp Tokyo#18 2016/07/20

@ Fork Inc.

Welcome to freeCodeCamp Tokyo meetup!

Who am I?Tanoue Kenta

Web Programmer

Ruby on Rails Rust

React

“Less is more”

What is freeCodeCamp?

Today's schedule

19:00~ Opening 19:10~ Pair programming 19:40~ Presentation 20:00~ Drinking party 🍺 (fee: 500 yen)

Pair programming

Design quality Learning

Two programmers work together at one workstation. One, the driver, writes code while the other, the navigator, reviews each line of code as it is typed in.

https://en.wikipedia.org/wiki/Pair_programming

Better code (in my opinion)Readability

Maintainability

var i = 5 What does “i” variable means?

function calMaxAndExcludeOddNumbersInArr(arr)Too many roles!

Modern Javascript (ES2015)

Better code part2

https://github.com/metagrover/ES6-for-humans https://babeljs.io/docs/learn-es2015/

Arrowsvar plus = (x, y) => { return x + y; };

Classesclass Human { constructor(name) { this.name = name; } }

Array Spreadfunction f(x, ...y) { return x * y.length; } f(3, "hello", true) == 6

• Array Map, Filter, Reduce (Functional Programming)

Better code part3

MAP Filter Reduce

Array Map, Filter and Reduce in JS | Aten Design Group http://atendesigngroup.com/blog/array-map-filter-and-reduce-js

Today’s challenges

Return Largest Numbers in Arrayshttps://www.freecodecamp.com/challenges/return-largest-

numbers-in-arrays

DNA Pairinghttps://www.freecodecamp.com/challenges/dna-pairing

Have a nice code!

sample codeReturn Largest Numbers in Arrays

https://gist.github.com/regonn/768c63fed15f6b728ef1d78acb949c52

DNA Pairing

https://gist.github.com/regonn/460f6fb826a4bb94f3fc4f2468fa027a