lodash func

lodash func

by 郭 凡

HTML

<script src="//cdn.bootcss.com/lodash.js/4.6.1/lodash.js"></script>

JavaScript

//lodash函数种种

//bind

//使用bind显示绑定this
function say(){
    return 'Say ' + this.what;
}
let sayHello = _.bind(say, {what: 'hello'});//this-->{what : 'helo'}
console.log(sayHello());

//使用bind,从实参中获取
function sayWhat(what){
    return 'Say ' + what;
}
let sayHaha = _.bind(sayWhat, {name : 'this'});//
console.log(sayHaha('haha'));

//after
var complete= 0,
    collection= _.range(9999999),
    progress= _.noop;//return undefined

function work(value){
    progress();
}

function reportProgress(){
    console.log(++complete + '%');//记录进度
    //after的第一个形参表示先执行n-1次reportProgress，花费n-1次相当的时间，到n次的时候正真执行reportProgress
    //本方法也实现了递归
    progress=complete<100? _.after(0.01*collection, reportProgress) : _.noop;
}

//先把进度启动起来
reportProgress();

//遍历集合的过程就是执行progress方法的过程
//而progress的执行取决于变量complete的值是否小于100
_.forEach(collection, work);