在JavaScript中从数组中查找索引号

Question

我想遍历元素数组并找到与某些条件匹配的元素的索引号。采取以下数组：

services: [
  { _id: <ObjectId>,
    name: "initiating"
  },
  { _id: <ObjectId>,
    name: "evaluating"
  },
  { _id: <ObjectId>,
    name: "servicing"
  },
]

我将如何遍历此数组，并在属性“名称”等于“求值”的对象（即-数组元素＃1）中拉出对象的数组索引号？

Answer 1

尝试Array.prototype.findIndex：

const services = [
  { _id: 1,
    name: "initiating"
  },
  { _id: 2,
    name: "evaluating"
  },
  { _id: 3,
    name: "servicing"
  },
];

console.log(
    services.findIndex(({ name }) => name === 'evaluating')
);

Answer 2

extResult

Answer 3

let services = [{
    _id: 0,
    name: "initiating"
  },
  {
    _id: 1,
    name: "evaluating"
  },
  {
    _id: 2,
    name: "servicing"
  },
];

let index = services.findIndex(item => item.name === "evaluating");
document.write(index);

这将在搜索每个对象的name属性并将其与“评估”进行比较之后返回索引。

Answer 4

您可以使用.reduce()：

var services = [
    {
        _id: '<ObjectId>',
        name: "initiating"
    },
    {
        _id: '<ObjectId>',
        name: "evaluating"
    },
    {
        _id: '<ObjectId>',
        name: "servicing"
    },
];
var idx = services.reduce((x, ele, idx) => (ele.name=='evaluating') ? idx : x, -1);

console.log(idx);