1 <!DOCTYPE html> 2 <html lang="en"> 3 4 <head> 5 <meta charset="UTF-8"> 6 <meta name="viewport" content="width=device-width, initial-scale=1.0"> 7 <title>Document</title> 8 </head> 9 10 <body> 11 <script> 12 13 //需求，为stus添加一个属性，获取score分数的总和 14 var stus = { 15 scores: [ 16 { name: "张三", score: 65 }, 17 { name: "李四", score: 86 }, 18 { name: "王五", score: 39 }, 19 { name: "赵六", score: 89 }, 20 ] 21 }; 22 23 //为 stus 添加一个属性 total 获取总数 24 Object.defineProperties(stus, { 25 total: { 26 get: function(){ 27 //声明一个变量 28 let t = 0; 29 for(let i = 0;i<this.scores.length;i++){ 30 t += this.scores[i].score;//5 31 } 32 return t; 33 }, 34 enumerable: true //可遍历 35 } 36 }); 37 38 // console.log(stus); 39 // for(let i in stus){ 40 // console.log(i); 41 // } 42 43 //得到总数 44 console.log(stus.total); 45 46 </script> 47 </body> 48 49 </html>