_.按 lodash 過濾
您可以通過 lodash 使用過濾器方法迭代集合的元素，返回所有元素的數組謂詞返回truthy for。謂詞使用三個參數調用：（值，索引|鍵，集合）。它返回一個新數組
https://lodash.com/docs/4.17.15#filter
lodash 上的過濾器使用示例
var users = [{
'user': 'barney',
'age': 36,
'active': true
},
{
'user': 'fred',
'age': 40,
'active': false
},
{
'user': 'fred',
'age': 39,
'active': true
}
];
console.log("matches:", _.filter(users, function(o) {
return !o.active;
}));
// => [{ active: true, age: 36, user: "barney"}]
// The `_.matches` iteratee shorthand.
console.log("_.matches` iteratee", _.filter(users, {
'user': 'fred',
'active': true
}));
// => [{ active: true, age: 39, user: "fred"}]
// The `_.matchesProperty` iteratee shorthand.
console.log("matchs poperty", _.filter(users, ['active', false]));
// => objects for ['fred']
// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js"></script>
_.where by underscore.js
你還可以使用underscore.js 的where方法查看列表中的每個值，返回一個包含與屬性中列出的鍵值對匹配的所有值的數組。 _.where(list, properties)
_.where 用法示例 _.where(listOfPlays, {author: "Shakespeare", year: 1611});
您基本上可以在普通的 javascript 中使用過濾器方法
var peoples = [
{ "name": "bob", "dinner": "pizza" },
{ "name": "john", "dinner": "sushi" },
{ "name": "john", "dinner": "sushi" },
{ "name": "larry", "dinner": "hummus" },
{ "name": "john", "dinner": "pie" }
];
var dinner = peoples.filter(e=>e.name ==="john" && e.dinner==="sushi");
console.log(dinner)
您也可以使用 jquery grep
var peoples = [
{ "name": "bob", "dinner": "pizza" },
{ "name": "john", "dinner": "sushi" },
{ "name": "john", "dinner": "sushi" },
{ "name": "larry", "dinner": "hummus" },
{ "name": "john", "dinner": "pie" }
];
var dinner = $.grep(peoples, function(people) {
return people.name === "john" && people.dinner === "sushi";
});
console.log(dinner)
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
查找 vs 過濾器
var peoples = [
{ "name": "bob", "dinner": "pizza" },
{ "name": "john", "dinner": "sushi" },
{ "name": "john", "dinner": "sushi" },
{ "name": "larry", "dinner": "hummus" },
{ "name": "john", "dinner": "pie" }
];
var filterDinner = peoples.filter(e=>e.name ==="john" && e.dinner==="sushi");
// return all matching results
console.log('filter dinner -:', filterDinner);
var findDinner = peoples.find(e=>e.name ==="john" && e.dinner==="sushi");
//returns the first matching rslt
console.log('find dinner -:', findDinner);
不推薦使用 Find，因為它返回第一個匹配結果，并且假設我們有更多匹配結果，它們會被遺漏。
