从数组中过滤数据并将其分组在javascript 中？

Question

我有一个如下所示的数组

OStatus=["hold","approved","rejected","hold","approved","rejected","hold","approved"]

我想要这样的结果

Oinfo=["hold":3,"approved":3,"rejected":2].

Answer 1

假设您想生成一个对象，该对象将作为输入数组元素的键映射到作为每个元素计数的值，您可以使用 Array.reduce，如下所示：

Oinfo = OStatus.reduce((acc, x) => ({ ...acc, [x]: (acc[x] || 0) + 1 }), {})