完全匹配javascript时如何获取对象数组中的对象索引

Question

我有一个对象数组，当我获得匹配项时，我想获取对象在数组中的索引。

我有如下数组：

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，我正在使用indexOf ，它最初可以工作，但现在不能正常工作。 返回-1 。

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

整体应该在数组中匹配，并且应该返回该对象的索引。 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

无法使用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。 这是一个例子：

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。 如果需要比较更多属性，则显然可以使用&&运算符添加其他相等性检查（例如element.name === find.name ）。

Answer 3

如果我们生活在_.lodash世界中， _.lodash这行之有效，因为lodash将深入研究对象 ：

 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，显然它不是高效的，并且指出，如果道具的顺序不同，这种方法将行不通。

 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);