CatalogES8增加了一个快速遍历对象的新方法Object.keys()返回一个数组条件过滤器Object.values()Object.entries()可以把一个对象变成一个可遍历的对象，可以传递给一个Map，成为一个地图objectforprocessing操作ES6-ES10学习布局ES8新增快速遍历对象的方法Object.keys()参数为目标对象返回由指定对象的key组成的数组返回数组ES5letgrade={"lilei":96,"hanmeimei":99}letresult=[]for(letkingrade){result.push(k)}console.log(result)//["lilei","hanmeimei"]ES8letgrade={"lilei":96,"hanmeimei":99}console.log(Object.keys(grade))//["lilei","hanmeimei"]条件过滤器ES5letgrade={"lilei":96,"hanmeimei":99}letresult=[]for(letkingrade){if(k==='lilei'){result.push(k)}}console.log(result)//["lilei"]ES8letgrade={"lilei":96,"hanmeimei":99}console.log(Object.keys(grade).filter(item=>item==='lilei'))//["lilei"]//返回一个数组，然后就可以对数组进行合并、替换、搜索Object.values()参数为目标对象，返回值数组letgrade={"lilei":96,"hanmeimei":99}console.log(Object.values(grade))//[96,99]console.log(Object.values(grade).filter(item=>item>97))//[99]Object.entries()可以转对象进入可遍历对象可以结合ES6（十五）-lteratoruseletgrade={"lilei":96,"hanmeimei":99}for(let[k,v]ofObject.entries(grade)){console.log(k,v)}//lilei96//hanmeimei99可以转为Map，成为地图对象进行操作。本质还是让对象可以遍历，符合迭代器结构letgrade={"lilei":96,"hanmeimei":99}letmap1=newMap(Object.entries(grade))map1.get("lilei")//96ES6-ES10学习图
