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JavaScript Advanced
1

JavaScript Advanced

03.11.2022
JavaScript Advanced
2

Destructure Object

js

const info = {
    name: 'ls',
    desc: 'lists files'
};

const { name } = info;
console.log('name', name);
03.11.2022
JavaScript Advanced
3

Destructure Array

js

const items = ['apple', 'peach', 'cherry'];
const [ apple, ...rest ] = items;
03.11.2022
JavaScript Advanced
4

Destructure as clone

js
const info = {
    name: 'ls',
    desc: 'lists files'
};

const copy = { ...info };
03.11.2022
JavaScript Advanced
5

Short Attributes

js
const name = 'ls';
const desc = 'lists files';

const command = {
    name: name,
    desc: desc
};

// kurz
const command = {
    name,
    desc
}
03.11.2022
JavaScript Advanced
6

Methode, welche eine Object returned

js
const getCmd = (name) =>  {
    return  {
        name,
        desc: "unspecified"
    }
};

// short
const getCmd = (name) => ({
        name,
        desc: "unspecified"
    }
);
03.11.2022
JavaScript Advanced
7

Strictly equals ===

js

1 == '1' // true
1 === '1' // false
0 == false // true
0 === false // false
03.11.2022
JavaScript Advanced
8

Entries

js
const cmd = {
    name: 'ls',
    desc: 'lists files'
};

for(const [k,v] of Object.entries(cmd)) {
    console.log(`${k}: ${v}`);
}
03.11.2022
JavaScript Advanced
9

Nullish ??

  • returned rechte Seite, falls Ausdruck null oder undefined, 0 oder ''.
js
let a = null;
const cmd = a ?? "ls";

let b = "cp";
const cmd1 = b ?? "ls";
03.11.2022
JavaScript Advanced
10

JavaScript Module

js

// bindet die axios library ein
import axios from `axios`;

RegEx

  • RegEx ist in der Sprache verbaut
js
const regex = /^(.*)?=(.*)?$/;
const r = "ls=lists files in groups".match(regex);
03.11.2022