UnderscoreJS：比较两个数组

Question

我目前有两个数组，我想将它们与另一个数组进行比较：

数组一：

var allCategories =
[
 { utilization:"license", id:"450", type: "MainCategory" },
 { utilization:"rating", id:"451", type: "SubCategory" },
 { utilization:"medical", id:"452", type: "MainCategory" },
 { utilization:"other", id:"453", type: "MainCategory" }
];

数组二：

var allKinds = 
[
 { name:"name1", id:"450", type: "FAA" },
 { name:"name2", id:"451", type: "FAA" },
 { name:"name3", id:"451", type: "FAA" },
 { name:"name4", id:"451", type: "FAA" },
 { name:"name5", id:"451", type: "SPA" },
 { name:"name6", id:"451", type: "SPA" },
 { name:"name7", id:"452", type: "FBC" },
 { name:"name8", id:"453", type: "SPA" }
];

我想做的是比较从 "Array Two" 中检索的项目与利用率："license"、"medical" 和 "other".

目前我已经从 "Array One" 中提取了 ID：

var categories = _.filter(allCategories, function(obj) {
  return obj.utilization === 'license' || obj.utilization === 'medical' || obj.utilization === 'other';
});
var category_ids = _.pluck(categories, 'id');

第二部分，我好像想不通：如何将 "Array one" [450, 452, 453] 的结果与 "Array Two" 中的项目进行比较以检索具有 id 的项目。

这是一个 jsfiddle： https://jsfiddle.net/7n9pjrc9/

Answer 1

一个简单的解决方案是通过检查 category_ids 是否包含对象 id 来过滤您的列表：

var r1 = _.filter(allKinds, function(o) {
    return _.contains(category_ids, o.id);
});
console.log(r1);

或者，如果您愿意，可以根据您选择的 ID 的哈希值进行过滤

var hashed = {};
_.each(categories, function(o) {
    hashed[o.id] = true;
});
var r2 = _.filter(allKinds, function(o) {
    return hashed[o.id];
});
console.log(r2);

还有一个演示

var allCategories =
[
 { utilization:"license", id:"450", type: "MainCategory" },
 { utilization:"rating", id:"451", type: "SubCategory" },
 { utilization:"medical", id:"452", type: "MainCategory" },
 { utilization:"other", id:"453", type: "MainCategory" }
];

var allKinds = 
[
 { name:"name1", id:"450", type: "FAA" },
 { name:"name2", id:"451", type: "FAA" },
 { name:"name3", id:"451", type: "FAA" },
 { name:"name4", id:"451", type: "FAA" },
 { name:"name5", id:"451", type: "SPA" },
 { name:"name6", id:"451", type: "SPA" },
 { name:"name7", id:"452", type: "FBC" },
 { name:"name8", id:"453", type: "SPA" }
];


var categories = _.filter(allCategories, function(obj) {
  return obj.utilization === 'license' || obj.utilization === 'medical' || obj.utilization === 'other';
});
var category_ids = _.pluck(categories, 'id');

var r1 = _.filter(allKinds, function(o) {
 return _.contains(category_ids, o.id);
});
console.log(r1);

var hashed = {};
_.each(categories, function(o) {
 hashed[o.id] = true;
});
var r2 = _.filter(allKinds, function(o) {
 return hashed[o.id];
});
console.log(r2);

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