92hackers

const binary = 0b1111
//=> 15

const oct = 0o1111
//=> 585

const decimal = 1111
// => 1111

const hex = 0x1111

92hackers

const value = Number(amount)

this.validateFaield = !isNaN(value) ? value > balance : true
  ||
  ||
this.validateFailed = !(value <= balance)

// compare NaN value always return false.

92hackers

schema	type	description
id	number	id of current instance
created_at	date	when instance created?
updated_at	date	when instance updated?
status	[1,2,3]	life status of instance

92hackers

Project Title

One Paragraph of project description goes here

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. See deployment for notes on how to deploy the project on a live system.

Prerequisites

92hackers

[
  { "key": "ctrl+`", "command": "workbench.action.focusActiveEditorGroup", "when": "terminalFocus" },
  { "key": "ctrl+`", "command": "workbench.action.terminal.focus", "when": "!terminalFocus" }
]

// Paste above code into   F1: Open KeyboardShortcuts preferences.  yourself keybinds.json

92hackers

// regex 分组的一个好例子
const pattern = /^(0*([1-9]\d{1,3})\ +)?([1-9]\d{7,})$/
const str = '086 18118771840'

pattern.exec(str)
/* =>  [ '086 18118771840', '086 ', '86', '18118771840' ]
 *  这里，用正则来匹配想要的字段，加上括号，即可自动分组，
 *  应用： 根据条件提取字段，分组甚至能够在正则表达式里面直接使用。
 */

92hackers

// 1, Object.is

Object.is('hello', 'hello')
// => true

Object.is(+0, -0)
// => false

Object.is(NaN, NaN)
// => true

92hackers

'C:\Users\Administrator/Desktop/7-42.pdf'  is wrong.
should be 'C:\\Users\\Administrator/Desktop/7-42.pdf'

because \ is preserved to escape character.

const str = 'C:\\Users\\Administrator/Desktop/7-42.pdf'
str.replace(/\//g, '\\')
// => 'C:\\Users\\Administrator\\Desktop\\7-42.pdf'

92hackers

Objects can be created with computed keys, so es6.ruanyifeng.com is not enough.

const obj = {
  [variable]: value,
}

Reduce, the simplest way to accummulate datas. reduce set first item as initial value default.

const total = ['age', 'name', 'favourite'].map(key => dataLists.reduce((sum, data) => ({

92hackers

#! /usr/bin/env bash

# sudo passwd root: set password for root user
sudo passwd root  # for root user
sudo passwd $USER  # for current logged in user.

# Add a new user
sudo adduser <qm>

# add epel yum repository