如何从对象数组中过滤数据

Question

Hi can anyone help me create an array of objects where the array has the object which has the highest version of a particular event id

Here is my array:

[{ version: 1, eventId: 12, id: 22 },
 { version: 2, eventId: 12, id: 23 }, 
 { version: 3, eventId: 12, id: 24 }, 
 { version: 1, eventId: 13, id: 25 }, 
 { version: 2, eventId: 13, id: 26 }]

Expected result

[{ version: 3, eventId: 12, id: 24 }, { version: 2, eventId: 13, id: 27 }]

Answer 1

Here is what you want:

 const ar = [{ version: 1, eventId: 12, id: 22 }, { version: 2, eventId: 12, id: 23 }, { version: 3, eventId: 12, id: 24 }, { version: 1, eventId: 13, id: 25 }, { version: 2, eventId: 13, id: 26 }]; const res = Array.from(ar.reduce((a, c) => { if (a.has(c.eventId)) { if (c.version > a.get(c.eventId).version) { a.set(c.eventId, c) } } else { a.set(c.eventId, c) } return a; }, new Map()).values()) console.log(res);

Answer 2

sort by the highest and then use filter

 array=[{ version: 1, eventId: 12, id: 22 }, { version: 2, eventId: 12, id: 23 }, { version: 3, eventId: 12, id: 24 }, { version: 1, eventId: 13, id: 25 }, { version: 2, eventId: 13, id: 26 }, { version: 3, eventId: 13, id: 27 }] vn=array.sort((a,b)=>b.id-a.id)[0].version res=array.filter(o=>o.version==vn) console.log(res)