Question

我想从Collections过滤掉两个obj，从服务器获取conditionArr，所以它是不可预测的。

我的代码是：

var users = [{
         user: 'barney',
         age: 36,
         active: true
     },
     {
         user: 'fred',
         age: 40,
         active: false
     },
     {
         user: 'travis',
         age: 37,
         active: true
     }
 ];
 // the Array fetch from Server, so it's unpredictable.
 var conditionArr = [{
     user: 'barney'
 }, {
     user: 'fred'
 }];
 // _.filter
 result = _.filter(users, conditionArr);

我的预期输出

// expect results:
 [{
         user: 'barney',
         age: 36,
         active: true
     },
     {
         user: 'fred',
         age: 40,
         active: false
     }
 ]

真实结果：

[]

THX。

----------- ----------分频器
我找到了一个更好的方法：

result =  _.map(conditionArr, (con) => ({
    ...con,
   ...(_.find(users, { user: con.user })),
}))

... THX

Answer 1

只需使用array.filter：

var users = [
 { user: 'barney', age: 36, active: true },
 { user: 'fred',  age: 40, active: false },
 { user: 'travis', age: 37, active: true}
];

var result = users.filter(({user}) => user === 'barney' || user === "fred");
console.log(result);

Answer 2

使用_.intersectionBy()：

＆＃13;

var users = [{"user":"barney","age":36,"active":true},{"user":"fred","age":40,"active":false},{"user":"travis","age":37,"active":true}];

 var conditionArr = [{"user":"barney"},{"user":"fred"}];

 var result = _.intersectionBy(users, conditionArr, 'user');
 
 console.log(result);

＆＃13;

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js"></script>

＆＃13;

Answer 3

如果您必须使用lodash实现此目的，您可以采用与array.filter

相同的方式

_.filter(users, ({user}) => user === 'barney' || user === 'fred');

Answer 4

与许多其他lodash函数一样，_. filil将函数作为第二个参数（将数组中的每个元素作为参数），如果函数返回true，则该元素保留在结果中。

var users = [
     { user: 'barney', age: 36, active: true },
     { user: 'fred', age: 40, active: false },
     { user: 'travis', age: 37, active: true }
 ];

// the Array fetch from Server, so it's unpredictable.
var conditionArr = [
  { user: 'barney'},
  { user: 'fred'}
];
 
 // Simplified condition a bit. cond = ['barney', 'fred'];
var cond = _.map(conditionArr, cond => cond.user);
 
 // _.filter
var result = _.filter(users, user => _.indexOf(cond, user.user) !== -1);

console.log('result', result);

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.5/lodash.min.js"></script>

Answer 5

在_.filter方法中，您需要传递如下示例

的功能

_.filter(users, function(o) { return !o.active; });

var users = [{
    user: 'barney',
    age: 36,
    active: true
  },
  {
    user: 'fred',
    age: 40,
    active: false
  },
  {
    user: 'travis',
    age: 37,
    active: true
  }
];


// _.filter
var result = _.filter(users, function(obj) { return obj.user=='barney'||obj.user=='fred' });

console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.core.js"></script>

Answer 6

use native js like -

let userSubset = users.map(function(obj, index) {

   if (obj.user === "barney" || obj.user === "fred") return obj;
}).filter(Boolean);

console.log(userSubset);

// {user: "barney", age: 36, active: true}
// {user: "fred", age: 40, active: false}

lodash _.filter如何过滤多条件？

6 个答案: