javascript - 如何将具有重复值的数组映射到 Javascript 中的唯一数组？

Question

我有以下数组:

var tst = 
[
 {"topicId":1,"subTopicId":1,"topicName":"a","subTopicName":"w"},
 {"topicId":1,"subTopicId":2,"topicName":"b","subTopicName":"x"},
 {"topicId":1,"subTopicId":3,"topicName":"c","subTopicName":"y"},
 {"topicId":2,"subTopicId":4,"topicName":"c","subTopicName":"z"}
]

有没有一种简单的方法可以将其映射到这种数组，其中 topicId > id 和 topicName > name:

var t = 
[
  {"id":1,"name":"a"},
  {"id":2,"name":"c"}
]

我正在使用现代浏览器，如果有帮助的话我也有 _lodash。请注意，tst 数组中大约有 100 行，因此我不需要非常优化的解决方案。一个简单且易于维护的解决方案更为重要。

Answer 1

最近

_.uniqBy is now preferable

Full working example here

var tst = [
 {"topicId":1,"subTopicId":1,"topicName":"a","subTopicName1":"w"},
 {"topicId":2,"subTopicId":2,"topicName":"b","subTopicName2":"x"},
 {"topicId":3,"subTopicId":3,"topicName":"c","subTopicName3":"y"},
 {"topicId":1,"subTopicId":4,"topicName":"c","subTopicName4":"z"}
];

var result = _.map(_.uniqBy(tst, 'topicId'), function (item) {
    return {
        id: item.topicId,
        name: item.topicName
    };  
});

console.log(result);

<小时/>

遗产

http://lodash.com/docs#uniq是一个好的开始

_.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');

您的代码将如下所示，以通过 id 获取唯一的主题

var t = _.uniq(tst, 'topicId');

编辑

我做了一个jsfiddle

http://jsfiddle.net/q5HNw/

更新

删除了不必要的名称唯一性

http://jsfiddle.net/q5HNw/1/