具有多个值的键上的lodash过滤器 [英] lodash filter on key with multiple values
本文介绍了具有多个值的键上的lodash过滤器的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我试图在 lodash
javascript library
中找到如何找到键的多个值的对象过滤器数组. 类似于SQL的东西-(val1,val2)中的WHERE KEY
I am trying to find out in lodash
javascript library
, how to find out filter array of objects multiple values of key. something similar to SQL - WHERE KEY in (val1, val2)
说了下面的例子:
var users = [
{ 'user': 'barney', 'age': 36, 'active': true },
{ 'user': 'fred', 'age': 40, 'active': false },
{ 'user': 'Avding', 'age': 34, 'active': true }
];
_.filter(...)
如何查找年龄在(34,36)岁的用户? 数字还可以更改运行时间
推荐答案
Lodash的过滤器接受一个谓词.您可以使用部分应用程序创建谓词,因此可以轻松更改值:
Lodash's filter accepts a predicate. You can create the predicate using partial application, so you can change the values easily:
var users = [
{ 'user': 'barney', 'age': 36, 'active': true },
{ 'user': 'fred', 'age': 40, 'active': false },
{ 'user': 'Avding', 'age': 34, 'active': true }
];
var predicate = function(start, end) {
return function(user) {
return _.inRange(user.age, start, end + 1);
}
}
var result = _.filter(users, predicate(34, 36));
console.log('inRange', result);
/** is equal predicate **/
var predicate = function() {
var args = _.toArray(arguments);
return function(user) {
var equalToUserAge = _.partial(_.isEqual, user.age);
return args.some(equalToUserAge);
}
}
var result = _.filter(users, predicate(34, 40));
console.log('equals', result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.4/lodash.min.js"></script>
您也可以使用香草JS轻松完成此操作(示例使用ES6):
You can also do this easily with vanilla JS as well (the example uses ES6):
var users = [
{ 'user': 'barney', 'age': 36, 'active': true },
{ 'user': 'fred', 'age': 40, 'active': false },
{ 'user': 'Avding', 'age': 34, 'active': true }
];
const predicate1 = (start, end) => ({ age }) =>
age >= start && age <= end;
const result1 = users.filter(predicate1(34, 36));
console.log('in range', result1);
const predicate2 = (...args) => ({ age }) =>
args.some((num) => age === num);
const result2 = users.filter(predicate2(34, 40));
console.log('is equal', result2);
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