javascript面向对象(七)_设置对象eric中的id可读-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_25707185/article/details/52971687

<!doctype html>
<html>
  <head>
    <title>标题</title>
    <meta charset="utf-8">
    <script>
      "use strict";
      var emp={
        id:1001,
        name:"eric",
        salary:10000
      };
      //id属性设置为只读
      //salary属性设置为禁止遍历
      //添加age属性，值为25，可读写，可遍历，可配置
      Object.defineProperties(emp,{
        id:{
          writable:false,
          configurable:false
        },
        salary:{
          enumerable:false,
          configurable:false,
        },
        age:{
          value:25,
          writable:true,
          enumerable:true,
          configurable:true
        }
      });
      //emp.id=1002;//报错！
      //delete emp.id;//报错！
      for(var key in emp){
        console.log(key+":"+emp[key]);
      }
      emp.age++;
      console.log(emp.age);//26
      /*设置id属性为只读
      Object.defineProperty(emp,"id",{
        writable:false,
        configurable:false//不可逆
      });*/
      //delete emp.id;//禁止删除
      /*
      var id_attrs=
      Object.getOwnPropertyDescriptor(
        emp,"id"
      );
      console.dir(id_attrs)
      */
      /*
      Object.defineProperty(emp,"id",{
        writable:true
      });//报错: 不允许重定义id属性
      */
      //emp.id=1002;//报错:不允许给只读属性赋值
      //console.log(emp.id);
      //设置salary属性不可遍历:
      /*
      Object.defineProperty(
        emp,"salary",{
          enumerable:false,
          configurable:false,
        }
      );
      for(var key in emp){
        console.log(key+":"+emp[key]);
      }
      console.log(emp.salary);
      */
      /*
      Object.defineProperty(emp,"age",{
        value:25,
        writable:true,
        enumerable:true,
        configurable:true,
      });
      console.dir(
        Object.getOwnPropertyDescriptor(
          emp,"age"
        )
      );
      emp.age++;
      console.log(emp.age);
      */
    </script>
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</html>