lodash使用值数组过滤集合

Question

我想使用属性值数组过滤集合.给定一组ID,返回具有匹配ID的对象.是否有使用lodash/的快捷方法underscore？

var collections = [{ id: 1, name: 'xyz' },
                   { id: 2,  name: 'ds' },
                   { id: 3,  name: 'rtrt' },
                   { id: 4,  name: 'nhf' },
                   { id: 5,  name: 'qwe' }];
var ids = [1,3,4];

// This works, but any better way?

var filtered = _.select(collections, function(c){    
    return ids.indexOf(c.id) != -1
});

Answer 1

如果你要经常使用这种模式,你可以像下面那样创建一个mixin,但它没有做与原始代码不同的任何有趣的事情.它只是让开发人员更友好.

_.mixin({
  'findByValues': function(collection, property, values) {
    return _.filter(collection, function(item) {
      return _.contains(values, item[property]);
    });
  }
});

然后你可以像这样使用它.

var collections = [
    {id: 1, name: 'xyz'}, 
    {id: 2,  name: 'ds'},
    {id: 3,  name: 'rtrt'},
    {id: 4,  name: 'nhf'},
    {id: 5,  name: 'qwe'}
];

var filtered = _.findByValues(collections, "id", [1,3,4]);

更新 - 以上答案陈旧而笨重.请使用Adam Boduch的答案获得更优雅的解决方案.

_(collections)
  .keyBy('id') // or .indexBy() if using lodash 3.x
  .at(ids)
  .value();

Answer 2

一个简洁的lodash解决方案,它使用indexBy()和at().

_(collections)
    .indexBy('id')
    .at(ids)
    .value();

Answer 3

我们也可以像这样过滤

var collections = [{ id: 1, name: 'xyz' },
            { id: 2,  name: 'ds' },
            { id: 3,  name: 'rtrt' },
            { id: 4,  name: 'nhf' },
            { id: 5,  name: 'qwe' }];



        var filtered_ids = _.filter(collections, function(p){
            return _.includes([1,3,4], p.id);
        });

        console.log(filtered_ids);

Answer 4

这对我很有用：

let output = _.filter(collections, (v) => _.includes(ids, v.id));

Answer 5

我喜欢jessegavin的答案,但我使用lodash-deep进行深度属性匹配.

var posts = [{ term: { name: 'A', process: '123A' } }, 
             { term: { name: 'B', process: '123B' } }, 
             { term: { name: 'C', process: '123C' } }];

var result = _.filterByValues(posts, 'term.process', ['123A', '123C']);
// results in objects A and C to be returned

的jsfiddle

_.mixin({
    'filterByValues': function(collection, key, values) {
        return _.filter(collection, function(o) {
            return _.contains(values, resolveKey(o, key));
        });
    }
});

function resolveKey(obj, key) {
    return (typeof key == 'function') ? key(obj) : _.deepGet(obj, key);
}

如果您不信任lodash-deep或者您希望支持名称中包含点的属性,那么这是一个更具防御性且更强大的版本:

function resolveKey(obj, key) {
    if (obj == null || key == null) {
        return undefined;
    }
    var resolved = undefined;
    if (typeof key == 'function') {
        resolved = key(obj);
    } else if (typeof key == 'string' ) {
        resolved = obj[key];
        if (resolved == null && key.indexOf(".") != -1) {
            resolved = _.deepGet(obj, key);
        }
    }
    return resolved;
}