Question

我想问一下，为了达到这个目的，我是否有更好的解决方案：

输入

  arr = [
     {value:1, role:""},
     {value:2, role:""},
     {value:4, role:""},
     {value:5, role:""}
  ];

输出

  outputArr = [1, 2, 4, 5];

到目前为止，我的解决方案是：

  for(var i = 0; i < arr.length; i++){
    outputArr.push(arr[i].value);
  }

但是有更好的方法吗？

Answer 1

您可以改用Array#map()：

let arr = [
     {value:1, role:""},
     {value:2, role:""},
     {value:4, role:""},
     {value:5, role:""}
  ];
  
let output = arr.map(el => el.value);

console.log(output)

Answer 2

  let arr = [
     {value:1, role:""},
     {value:2, role:""},
     {value:4, role:""},
     {value:5, role:""}
  ];

  let outputArr = arr.map((e)=>e.value)

  console.log(outputArr)

Answer 3

查看此

arr = [
     {value:1, role:""},
     {value:2, role:""},
     {value:4, role:""},
     {value:5, role:""}
  ];
var d=arr.map((x)=>x.value)
console.log(d)

您可以检查哪一个速度更快

arr = [
     {value:1, role:""},
     {value:2, role:""},
     {value:4, role:""},
     {value:5, role:""}
  ];

console.time('Using Loop');
var aOut=[];
for(var i = 0; i < arr.length; i++){
   aOut.push(arr[i].value);
}
console.timeEnd('Using Loop')


console.time('Using Map');
var bOut = arr.map((e)=>e.value)
console.timeEnd('Using Map')

如何将对象数组中的字段值复制到另一个数组中

3 个答案: