javascript - JavaScript将数组按值转换为分组对象

我有一个数组：

["car1-coupe", "car2-convertible", "car2-hatchback", "car2-estate", "car3-hatchback", "car3-estate"]

该数组可以具有不同的汽车组，我想将其转换为以下形式：

[{
    car1: ["car1-coupe"]
},{
    car2: ["car2-convertible", "car2-hatchback", "car2-estate"]
},{
    car3: ["car3-hatchback", "car3-estate"]
}]

如何在JavaScript或Underscore中执行此操作？

最佳答案

因此，假设这样的数组：

var a = ["car1-coupe", "car2-convertible", "car2-hatchback", "car2-estate", "car3-hatchback", "car3-estate"];

你可以这样做：

var b = a.reduce(function(prev, curr){
    var car = curr.split('-')[0]; // "get" the current car
    prev[car] = prev[car] || [];  // Initialize the array for the current car, if necessary.
    prev[car].push(curr);         // Add the current item to the array.
    return prev;
}, {});

这将返回以下对象：

{
    car1: ["car1-coupe"],
    car2: ["car2-convertible", "car2-hatchback", "car2-estate"],
    car3: ["car3-hatchback", "car3-estate"]
}