使用下划线groupby按颜色分组汽车数组 [英] Using underscore groupby to group an array of cars by their colour
问题描述
我有一系列汽车。
car = {
make: "nissan",
model: "sunny",
colour: "red"
};
我如何使用underscore.js按颜色对数组进行分组?
How would I use underscore.js to group the array by colour?
我尝试了几个组合,但我不确定如何指定我的迭代器条件:
I've tried a few combos but I'm not really sure how to specify my iterator condition:
var carsGroupedByColor = _.groupBy(cars, false, colour);
var carsGroupedByColor = _.groupBy(vars, false, function(cars){ return cars[colour]; };
它们每次都返回数组中的所有内容。
They all return everything in the array each time.
推荐答案
你不需要 false
第二个参数,以下内容将起作用:
You don't need the false
second argument, the following will work:
var redCars = _.groupBy(cars, 'colour');
请注意,第二个参数可以是 function
或 string
。如果是字符串
按该属性名称的下划线组。
Note that the second parameter can either be a function
or a string
. If it's a string
Underscore groups by that property name.
取自文档:
将一个集合拆分成集合,分组通过迭代器运行每个
值的结果。如果迭代器是字符串而不是函数,
由迭代器。
Splits a collection into sets, grouped by the result of running each value through iterator. If iterator is a string instead of a function, groups by the property named by iterator on each of the values.
这是一个工作示例。
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