如何在 lodash 中对对象使用数组过滤条件？

Question

如何在lodash中过滤对象年龄与另一个对象？但条件对象是数组..

var form = { type: ['xyz', 'abc'], name: 'pre-1' }

var items = [
 { type: 'xyz', name: 'pre-1' },
 { type: 'abc', name: 'pre-1' }, 
 { type: 'xyz', name: 'pre-2' }, 
]

const results = lodash.filter(items, form);

results 应该是 xyz 和 abc：

results = [{ type: 'xyz', name: 'pre-1' }, { type: 'abc', name: 'pre-1' }]

我可以使用filter 方法吗？

Answer 1

好吧，您可以使用 lodash 的自定义过滤方法。试试下面：

var form = { type: ['xyz', 'abc'], name: 'pre-1' }

var items = [
 { type: 'xyz', name: 'pre-1' },
 { type: 'abc', name: 'pre-1' }, 
 { type: 'xyz', name: 'pre-2' }, 
]

let filtered = _.filter(items, (item)=>{
    return form.type.indexOf(item.type) >= 0 && form.name == item.name
});

console.log(filtered);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js"></script>

Answer 2

var form = { type: ['xyz', 'abc'], name: 'pre-1' }

var items = [
 { type: 'xyz', name: 'pre-1' },
 { type: 'abc', name: 'pre-1' }, 
 { type: 'xyz', name: 'pre-2' }, 
]

var item = _.filter(items, i => {
 return form.type.indexOf(i.type) > -1 && form.name === i.name
});

console.log(item)

Answer 3

检查是否form.name === item.name，如果是，则使用Array.includes() 检查item.type 是否出现在form.type 中。

注意：我使用了 vanilla JS 过滤器并包含方法，但您可以将它们替换为 lodash 的 _.filter() 和 _.includes()。

const form = { type: ['xyz', 'abc'], name: 'pre-1' }

const items = [{"type":"xyz","name":"pre-1"},{"type":"abc","name":"pre-1"},{"type":"xyz","name":"pre-2"}]

const result = items.filter(item =>
  form.name === item.name && form.type.includes(item.type)
)

console.log(result)

lodash 的另一个选项是使用_.intersectionWith()，并在comperator 函数中检查项目的名称是否与表单的名称相同，并且类型中存在类型。

const form = { type: ['xyz', 'abc'], name: 'pre-1' }

const items = [{"type":"xyz","name":"pre-1"},{"type":"abc","name":"pre-1"},{"type":"xyz","name":"pre-2"}]

const result = _.intersectionWith(items, form.type, (item, type) =>
  form.name === item.name && item.type === type
)

console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js"></script>

Answer 4

如果您将您的项目reduce 到一个对象映射，其中可以通过type 和name 的组合找到项目，那么它可以是key 带或不带lodash 的简单映射：

var form = { type: ['xyz', 'abc'], name: 'pre-1' }

var items = [
 { type: 'xyz', name: 'pre-1' },
 { type: 'abc', name: 'pre-1' }, 
 { type: 'xyz', name: 'pre-2' }, 
].reduce((r,c) => (r[`${c.type}-${c.name}`] = c, r), {}) // convert to object map

let result = form.type.map(t => items[`${t}-${form.name}`]) // map by key

console.log(result)

使用 lodash，您可以使用 _.keyBy 和 _.map：

var form = { type: ['xyz', 'abc'], name: 'pre-1' }

var items = _.keyBy([
 { type: 'xyz', name: 'pre-1' },
 { type: 'abc', name: 'pre-1' }, 
 { type: 'xyz', name: 'pre-2' }, 
], x => `${x.type}-${x.name}`)

let result = _.map(form.type, t => items[`${t}-${form.name}`])

console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js"></script>

从性能的角度来看，这样您就处于O(N) 领域。

Answer 5

纯 JS 中的简单：

var form = { type: ['xyz', 'abc'], name: 'pre-1' }

var items = [
 { type: 'xyz', name: 'pre-1' },
 { type: 'abc', name: 'pre-1' }, 
 { type: 'xyz', name: 'pre-2' }, 
]

const res = items.filter(({ type, name }) => form.type.includes(type) && form.name == name);

console.log(res);

.as-console-wrapper { max-height: 100% !important; top: auto; }

如果你真的想，你可以像这样使用 Lodash 的 _.filter 方法：

var form = { type: ['xyz', 'abc'], name: 'pre-1' }

var items = [
 { type: 'xyz', name: 'pre-1' },
 { type: 'abc', name: 'pre-1' }, 
 { type: 'xyz', name: 'pre-2' }, 
]

const res = _.filter(items, ({ type, name }) => form.type.includes(type) && form.name == name);

console.log(res);

.as-console-wrapper { max-height: 100% !important; top: auto; }

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.js"></script>