Why do you use JavaScript

Transcript

1. Why do you use dynamically typed language? Jul. 6, 2019 Kazuhisa Kawashima
2. Who am I • Name : Kazuhisa Kawashima • Home : Shizuoka shi, aoi ku • Company : YUMEMI inc. (株式会社ゆめみ) • Job : Computer Engineer • Favorite computer language : Scala, TypeScript
3. What is Yumemi? Company Features • We are a software engineering company. • We value the growth of everyone. • All employees are CEOs. • The salary is decided by yourself. • We decide all things by the proposal request. Reference : https://note.mu/raykataoka/n/n50c282bcb305
4. My first time to meet JavaScript Long long ago… (Over 20 years ago) I made a web site. So, I used JavaScript by checking input parameters. After that I have not used JavaScript for a long time. Instead, I used ruby in a project. submit cancel e-mail : password : hogehoge@hogehoge.com Password is required!
5. I dislike a dynamically typed language. Because of … • Don’t check simple mistake before running. ◦ Missing a type ◦ Typo ◦ Missing number of arguments • Can’t use the IDE effectivery ◦ Autocomplete ◦ Refactoring
6. I want to make a web pages. I try to make the web pages as SPA. I need to use JavaScript to make the modern web pages.
7. Vue and TypeScript I found! How to make the web pages by statically typed language! Vue is … • Easy to understand • Supported TypeScript • Be able to use with modern tools
8. Sample code <template> <div> <p @click="clickDay(day)">{{ day.getDate() }}</p> </div> </template> <script lang="ts"> import { Component, Emit, Prop, Vue } from "vue-property-decorator"; @Component({ components: { } }) export default class Day extends Vue { @Prop({ default: false }) day!: Date; @Emit("clickDay") clickDay(day: Date) { } } </script> 5 The parent set value. This is Date type.
9. It’s time to use TypeScript! If you use TypeScript ... • The compiler check simple mistake before running. ◦ Missing a type ◦ Typo ◦ Missing number of arguments • You’ll be able to use the IDE effectivery ◦ Autocomplete ◦ Refactoring
10. Finally 　　We are hiring! Welcome those who want to work in Shizuoka with me! E-mail : k_kawashima@yumemi.co.jp
11. Thank you for listening!