<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> <script> // What you have var officers = [ {id:1,name:'andy',age:15,weight:60}, {id:2,name:'sam',age:20,weight:50}, {id:3,name:'julia',age:15,weight:40}, {id:4,name:'tom',age:25,weight:30} ] // What you need // [1,2,3,4] // forEach() // var officersIds = []; // officers.forEach(val => { // console.log(val) // officersIds.push(val.id) // }) // console.log(officersIds) // map const officersIds = officers.map(val=>val.id) // console.log(officersIds) // filter const teenager = officers.filter(officers => officers.age < 18) console.log(teenager) // {id: 1, name: "andy", age: 15, weight: 60} // {id: 3, name: "julia", age: 15, weight: 40} const adult = officers.filter(officers => officers.age > 18) console.log(adult) // {id: 2, name: "sam", age: 20, weight: 50} // {id: 4, name: "tom", age: 25, weight: 30} // reduce 可以直观的返回数组里面指定的一个值或者对象 // 所有职员的体重 const totalWeight = officers.reduce((param1,param2) => param1+param2.weight,0) console.log(totalWeight) //180 </script> </head> <body> </body> </html>
.map() .filter() .reduce() 的用法
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转载自www.cnblogs.com/andyZhang0511/p/12035316.html
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