[英]How to convert an array containing arrays of objects to single array witht hose object using Ramda expressions?
[英]How to map an array of objects to a single object using Ramda
我需要把这个:
let arr = [{ id: 1, name: 'rod'} , { id: 2, name: 'hey' }]
成:
mapO = { 1: 'rod', 2: 'hey' }
那就是我尝试过的:
let mapIdName = (o) => {
let ret = {};
ret[o["id"]] = o['name'];
return ret;
}
let mergeIdNames = R.mergeAll(R.map(mapIdName));
mergeIdNames(o)
与错误:
mergeIdNames is not a function
您可以使用R.indexBy
:
> R.map(R.prop('name'), R.indexBy(R.prop('id'), [{id: 1, name: 'rod'}, {id: 2, name: 'hey'}]))
{'1': 'rod', '2': 'hey'}
作为功能:
// f :: Array { id :: String, name :: a } -> StrMap a
const f = R.pipe(R.indexBy(R.prop('id')), R.map(R.prop('name')));
f([{id: 1, name: 'rod'}, {id: 2, name: 'hey'}]);
// => {'1': 'rod', '2': 'hey'}
即使使用Reduce也会导致相当简洁易读的代码:
reduce((acc, curr) =>
R.assoc(curr.id, curr.name, acc), {}, arr)
或用作功能:
const f = R.reduce((acc, curr) =>
R.assoc(curr.id, curr.name, acc), {})
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.