根据键值从Underscore.js中的对象数组中删除特定的重复项

Question

我有一个像这样的数组：

var array = [
      {"id":"A","type":"blue","rng":"50"},
      {"id":"A","type":"blue","rng":"75"},
      {"id":"A","type":"grey","rng":"76"},

      {"id":"B","type":"blue","rng":"50"},
      {"id":"B","type":"grey","rng":"85"},
      {"id":"B","type":"grey","rng":"86"},

      {"id":"C","type":"blue","rng":"50"},
      {"id":"C","type":"grey","rng":"65"}
    ]

注意：对象以随机顺序排列。

我需要过滤掉重复的"id":"*","type":"blue"和"id":"*","type":"grey" 和更高的 "rng" 。

所以最终结果是：

var result = [
      {"id":"A","type":"blue","rng":"50"},
      {"id":"A","type":"grey","rng":"76"},

      {"id":"B","type":"blue","rng":"50"},
      {"id":"B","type":"grey","rng":"86"},

      {"id":"C","type":"blue","rng":"50"},
      {"id":"C","type":"grey","rng":"65"}
    ]

我热衷于使用下划线，但也欢迎使用任何其他解决方案。

Answer 1

您可以使用哈希表和组合键作为对索引的引用。

 var data = [{ id: "A", type: "blue", rng: "50" }, { id: "A", type: "blue", rng: "75" }, { id: "A", type: "grey", rng: "76" }, { id: "B", type: "blue", rng: "50" }, { id: "B", type: "grey", rng: "85" }, { id: "B", type: "grey", rng: "86" }, { id: "C", type: "blue", rng: "50" }, { id: "C", type: "grey", rng: "65" }], result = data.reduce(function (hash) { return function (r, o) { var key = ['id', 'type'].map(function (k) { return o[k]; }).join('|'); if (!(key in hash)) { hash[key] = r.push(o) - 1; } else if (r[hash[key]].rng < o.rng) { r[hash[key]] = o; } return r; }; }(Object.create(null)), []); console.log(result); 

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Answer 2

您可以使用forEach()循环和一个对象作为thisArg参数来检查是否存在具有相同id|type对象。

 var array = [{"id":"A","type":"blue","rng":"50"},{"id":"A","type":"blue","rng":"75"},{"id":"A","type":"grey","rng":"76"},{"id":"B","type":"blue","rng":"50"},{"id":"B","type":"grey","rng":"85"},{"id":"B","type":"grey","rng":"86"},{"id":"C","type":"blue","rng":"50"},{"id":"C","type":"grey","rng":"65"}] var result = [] array.forEach(function(e) { // Create key with id and type var key = e.id + '|' + e.type; // Check if key exists in this object and if it doesn't create property with value of current value and push that value to result array if(!this[key]) this[key] = e, result.push(this[key]) else { // Otherwise check if rng of current element is < of rng of previous object with same key and if it is set rng to rng of current object if(e.rng < this[key].rng) this[key].rng = e.rng } }, Object.create(null)) console.log(result)