Question

我有一个对象数组，我想在获得匹配项时获取对象在数组中的索引。

我的数组如下：

let x = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}},
 .....
];

目前，我使用的indexOf最初可以正常工作，但现在无法正常工作。它返回-1。

let find = {name: "maggie", info: { id: 234, gender: "female", age: 22}};
let index = x.indexOf(find); // should return 1.

整体应在数组中匹配，并应返回该对象的索引。我该如何实现？我应该使用some()吗？

谢谢

Answer 1

您可以使用.find代替indexOf，因为2个对象永远都不相等（因为它们指向内存中的不同引用），这似乎是您作为参数传递的。

let x = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}}
];

let found = x.find(function(item) {
  // you can use the condition here
  return item.info.id === 564;
});

console.log(found);

要查找索引，可以改用.findIndex方法。

let x = [
    {name: "emily", info: { id: 123, gender: "female", age: 25}},
    {name: "maggie", info: { id: 234, gender: "female", age: 22}},
    {name: "kristy", info: { id: 564, gender: "female", age: 26}}
];

let foundIndex = x.findIndex(function(item) {
  // you can use the condition here
  return item.info.id === 564;
});

console.log(foundIndex);

Answer 2

无法通过JavaScript中的传统相等性来比较对象。而是使用ES6 findIndex方法将每个对象的属性与所需值进行比较。这是一个示例：

let x = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}}
];
let find = {name: "maggie", info: { id: 234, gender: "female", age: 22}};
let index = x.findIndex(element => element.info.id === find.info.id); // index === 1

id值似乎足以识别您的方案中的对象；如果您需要比较更多属性，则显然可以使用element.name === find.name运算符添加其他相等性检查（例如&&）。

Answer 3

如果我们生活在_.lodash的世界中，这将是可行的，因为lodash会走向deep on objects：

let data = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, age: 22, gender: "female"}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}},
];

let find = {name: "maggie", info: { id: 234, gender: "female", age: 22}};
let index = _.findIndex(data, (i) => _.isEqual(i, find))

console.log(index)  // 1

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

一种更野蛮的方法，显然是不并指出，如果道具的顺序不同，则不会起作用。

let data = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}},
];

var objectJSONs = data.map((i) => JSON.stringify(i))

let myJSON = JSON.stringify({name: "maggie", info: { id: 234, gender: "female", age: 22}});
let index = objectJSONs.indexOf(myJSON)

console.log(index) // 1

Answer 4

您可以使用下划线_.isEqual进行对象比较，并使用some（）或任何循环机制来迭代数组。

let iFoundIndex = -1;
let bFound = x.some((data,index) => {
                    if(_.isEqual(data,find){
                        iFoundIndex = index;
                        return true;
                    }
                    return false;
                  }
 //console.log(iFoundIndex);

完全匹配javascript时如何获取对象数组中的对象索引

4 个答案: