es6中比较有用的7个技巧小结

var arr = [1, 2, 3, 3, 4];
console.log(...new Set(arr))
>> [1, 2, 3, 4]

var myArray = [1, 0 , undefined, null, false];
myArray.filter(Boolean);
> > [1]
//是不是很简单, 只需要传入一个 Boolean 函数即可.

let dict = Object.create(null);
 
dict.__proto__ === "undefined" 

const page = {
 current: 1,
 pageSize: 10
}
 
const form = {
 name: "",
 sex: ""
}
 
const params = {...form, ...page};
 
/*
 {
  name: "",
  sex: "",
  current: 1,
  pageSize: 10
 }
*

const isRequired = () => { throw new Error('param is required'); };
 
const hello = (name = isRequired()) => { console.log(`hello ${name}`) };
 
// 这里将抛出一个错误,因为名字时必须
hello();
// 这也将抛出一个错误
hello(undefined);
 
// 正常
hello(null);
hello('David'); 

const obj = { x: 1 };
 
// Grabs obj.x as { x }
const { x } = obj;
 
// Grabs obj.x as { otherName }
const { x: otherName } = obj;

 function getQueryString(name) {
 var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)");
 var r = window.location.search.substr(1).match(reg);
 return r ? r[2] : null;
 }

// 假设地址栏中查询参数是这样 "?post=1234&action=edit"
 
var urlParams = new URLSearchParams(window.location.search);
 
console.log(urlParams.has('post')); // true
console.log(urlParams.get('action')); // "edit"
console.log(urlParams.getAll('action')); // ["edit"]
console.log(urlParams.toString()); // "?post=1234&action=edit"
console.log(urlParams.append('active', '1')); // "?post=1234&action=edit&active=1"