Question

我们有一个对象数组

var myArr = [ {name: "john", age:23}
              {name: "john", age:43}
              {name: "jim", age:101}
              {name: "bob", age:67} ];

如何从lAash获取myArr中名称为john的对象列表？

Answer 1

使用lodash _.filter方法：

_.filter(collection, [predicate=_.identity])

迭代集合的元素，返回所有元素的数组谓词返回truthy。使用三个参数调用谓词：（value，index | key，collection）。

将谓词作为自定义函数

 _.filter(myArr, function(o) { 
    return o.name == 'john'; 
 });

谓词作为过滤对象的一部分（_.matches iteratee简写）

_.filter(myArr, {name: 'john'});

谓词为[key，value] array （_.matchesProperty iteratee简写。）

_.filter(myArr, ['name', 'John']);

Answer 2

Lodash有一个“map”功能，就像jQuerys：

一样

var app = angular.module('plunker', []);

app.controller('MainCtrl', ['tempDataStorageService', function(tempDataStorageService) {

  var register = this;

  register.firstName = "";

    register.storedData = tempDataStorageService;

    register.test = function () {
      tempDataStorageService.setName(register.firstName);
    }

}]);


app.factory('tempDataStorageService', function() {
    // The service object
    var profile = {};

    profile.doctorFirstName = "No doctor data stored";

    //The functions

    profile.setName = function(data) {
        profile.doctorFirstName = data;
    }

    profile.getName = function() {
        return profile.doctorFirstName;
    }

    // return the service object
    return profile;
});

Answer 3

let myArr = [
    {name: "john", age:23},
    {name: "john", age:43},
    {name: "jim", age:101},
    {name: "bob", age:67},
];

// this will return old object (myArr) with items named 'john'
let list = _.filter(myArr, item => item.name === 'jhon');

//  this will return new object referenc (new Object) with items named 'john' 
let list = _.map(myArr, item => item.name === 'jhon').filter(item => item.name);

Answer 4



let myArr = [
    {name: "john", age:23},
    {name: "john", age:43},
    {name: "jim", age:101},
    {name: "bob", age:67},
];

let list = _.filter(myArr, item => item.name === "john");

Answer 5

使用lodash：

const myArr = [ {name: "john", age:23},
                {name: "john", age:43},
                {name: "jim", age:101},
                {name: "bob", age:67} ];

const johnArr = _.filter(myArr, person => person.name === 'john');
console.log(johnArr)

香草JavaScript：

const myArr = [ {name: "john", age:23},
                {name: "john", age:43},
                {name: "jim", age:101},
                {name: "bob", age:67} ];

const johnArr = myArr.filter(person => person.name === 'john');
console.log(johnArr);

Answer 6

**按姓名，年龄过滤** 另外，您可以使用地图功能

地图和过滤器之间的差异

1。 map -map（）方法创建一个新数组，并为每个数组元素调用一个函数。 map方法允许根据用户的喜好对数组中的项目进行操作，从而在全新的数组中返回所选操作的结论。例如，考虑以下数组：

2。 filter -filter（）方法创建一个数组，该数组填充了所有通过提供的函数实现的测试的数组元素。筛选方法非常适合于特定情况，在这些情况下，用户必须标识数组中具有共同特征的某些项目。例如，考虑以下数组：

`const users = [ 
           {name: "john", age:23},
           {name: "john", age:43},
           {name: "jim", age:101},
           {name: "bob", age:67} 
     ];

    const user = _.filter(users, {name : 'jim', age: 101});
    console.log(user);`

Answer 7

lodash还具有删除方法

 var myArr = [ {name: "john", age:23}
          {name: "john", age:43}
          {name: "jim", age:101}
          {name: "bob", age:67} ];

 var onlyJohn = myArr.remove( person => { return person.name == "john" })

使用基于属性值的lodash过滤对象数组

7 个答案:

使用lodash：

香草JavaScript：