JavaScript grammar

wuyijysx2025-05-14 20:12

general grammar

class to packet data

Use class to packet related const variables, with static to define class-level members that belong to the class itself rather than instances of the class, allowing direct access through the class name (e.g.,ApplePacket.CMD) without instantiation.

The key points about static in this context are:

Belongs to the class itself, not instances
Can be accessed directly through the class name
Shared across all uses of the class
No need to create an instance with new

javascript 复制代码

const CMD = {
    a: 1,
    b: 2
};
    
class BLEPacket {
    // Constants
    static CMD = {
    a: 1,
    b: 2
    };
...
}

ES6 语法

扩展运算符 ...
口诀：三个点，打散数组，逐个放进去
例子：

javascript 复制代码

  let arr = [1, 2];
  let more = [3, 4];
  arr.push(...more); // arr 变成 [1, 2, 3, 4]

解构赋值
口诀：左边是变量，右边是值，一一对应
例子：

javascript 复制代码

  let [a, b] = [1, 2]; // a=1, b=2
  let {name, age} = {name: 'Tom', age: 18}; // name='Tom', age=18

箭头函数 =>
口诀：箭头指向返回值，一行代码不用大括号
例子：

let add = (a, b) => a + b;
let double = x => x * 2;
模板字符串 - **口诀**：反引号包裹，${变量}插入- **例子**：js
let name = 'Tom';
let greeting = Hello, ${name}!;

javascript 复制代码

  let name = 'Tom';
  let greeting = `Hello, ${name}!`;