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Object.keys方法之详解

一、语法

      Object.keys(obj)参数：要返回其枚举自身属性的对象返回值：一个表示给定对象的所有可枚举属性的字符串数组

二、处理对象，返回可枚举的属性数组

      let person = { name: 'tom', age: 25, address: '南非',getName:function(){}}Object.keys(person) // ["name", "age", "address","getName"]

三、处理数组。返回索引值数组

      let arr = [1,2,3,4,5,6]Object.keys(arr) // ["0", "1", "2", "3", "4", "5"]

四、处理字符串，返回索引值数组

    let str = "object.obj字符串"Object.keys(str) // ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12"]

使用案例

    //get请求let url = 'http://localhost:8081'let data = { name: 'tom', age: 25, address: '南非' };let dataStr = '';//拼接字符串Object.keys(data).forEach(key => {dataStr += key + '=' + data[key] + '&'})console.log(dataStr)if (dataStr !== '') {//拼接字符串dataStr = dataStr.substring(0, dataStr.lastIndexOf('&'))url = url + '?' + dataStr;console.log(url)}      

五、常用技巧

    let person = {name:"张三",age:25,address:"深圳",getName:function(){}}Object.keys(person).map((key)=>{person[key] // 获取到属性对应的值，做一些处理})

六、Object.values()和Object.keys()是相反的操作，把一个对象的值转换为数组

    let strList = { name: 'tom', age: 25, address: '南非' };console.log(Object.values(strList))  //["tom", 25, "南非"]