如何从另一个数组中减去一个数组? [英] How can I subtract one array from another?

问题描述

我有两个数组:

var collectionA = [
    {'name': 'Brandon', 'age': '41'}
];
var collectionB = [
    {'name': 'Brandon', 'age': '41'},
    {'name': 'Tom', 'age': '25'},
    {'name': 'Jimmy', 'age': '36'},
    {'name': 'Brian', 'age': '36'}
];

如何创建第三个数组，它基本上是从 collectionB 中减去 collectionA 的结果?仅供参考:我在这个项目中使用了 Underscore 和 Backbone，并且很乐意使用其中一个.

How can I get create a third array that is basically the result of subtracting collectionA from collectionB? FYI: I'm using Underscore and Backbone in this project and would love to do this with one or the other.

第三个数组看起来像这样:

The third array would look like this:

var collectionC = [
    {'name': 'Tom', 'age': '25'},
    {'name': 'Jimmy', 'age': '36'},
    {'name': 'Brian', 'age': '36'}
];

推荐答案

解决方案

var collectionA = [
    {'name': 'Brandon', 'age': '41'},
    {'name': 'Tom', 'age': '25'},
    {'name': 'Jimmy', 'age': '36'},
    {'name': 'Brian', 'age': '36'}
];
var collectionB = [
    {'name': 'Brandon', 'age': '41'}
];
var subtract = function(a, b){
  var r = {};
  for(var i in a){
    var ai = a[i];
    for(var j in b){
      var bj = b[j];
      if(ai.name != bj.name || ai.age != bj.age){
       r[i] = ai;
      }
    }
  }
  return r;
};

var c = subtract(collectionA,collectionB);

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