实习日志-2

实习日志-2(javascript)

var a = {n:1};a.x= a = {n:2}; //此x时的a地址发生改变console.log(a.x);//console.log中的a是{n:2},该对象无x属性，输出undefind

function aname(){    console.log(arguments);}var a =[1,2,3];aname(...a);//1,2,3//`...`表示去结构化

//算符的优先级Only the top last level of an object property reference chain matters to the call-site. For instance:function foo() {   console.log( this.a );}var obj2 = {    a: 42,    foo: foo};var obj1 = {    a: 2,    obj2: obj2};obj1.obj2.foo(); // 42

//call function;const concatAll = (array,fn) => {let results = []for(const value of array)    results.push.apply(results, value);return results;}concatAll可拆解多个数组中的数组，将他们合成为一个数组。eg:arr = [[1,2,3,4],[5,6,7,8],[999,000]];concatAll(arr);//[1, 2, 3, 4, 5, 6, 7, 8, 999, 0]

小工具:代码实现库(可查询一些方法的实现原理)
underscore.js
lodash.js
——2017.7.18实习于
http://map.baidu.com/?newmap=1&s=con%26wd%3D%E6%9D%8F%E6%9E%97%E6%B9%BE%E8%90%A5%E8%BF%90%E4%B8%AD%E5%BF%83%26c%3D194&from=alamap&tpl=mapdots