如何 map 按所需 object 值分組的嵌套 arrays 數組

Question

我有一組消息，如下所示：

[
  { message: 'This is message', to: 4, from: 1},
  { message: 'This is response message', to: 1, from: 4 },
  { message: 'This is ANOTHER message with different sender', to: 1, from: 2 },
  { message: 'This is RESPONSE message to different sender', to: 2, from: 1 },
]

我有所有的消息，但它們沒有按用戶對用戶的對話分組。 我想要的是通過to和from對消息（在數組內）進行分組。

我怎樣才能達到以下結果：

[
  [
    { message: 'This is message', to: 4, from: 1},
    { message: 'This is response message', to: 1, from: 4 },
  ],
  [
    { message: 'This is ANOTHER message with different sender', to: 1, from: 2 },
    { message: 'This is RESPONSE message to different sender', to: 2, from: 1 }
  ],
]

簡而言之：

目前的結構是

// Individually structured messages
[message, message, message, message]

期望的結果：

// Grouped by user-to-user conversation
// [[Conversation1], [Conversation2]]
[[message, message], [message,message]]

我曾嘗試將 lodash 與return this._.values(this._.groupBy(this.messages, 'to')) ，但由於我需要按兩個標准對它們進行分組，所以我沒能想出邏輯。

Answer 1

Javascript 使用Array.reduce和Array.find實現

 const messages = [ { message: 'This is message', to: 4, from: 1}, { message: 'This is response message', to: 1, from: 4 }, { message: 'This is ANOTHER message with different sender', to: 1, from: 2 }, { message: 'This is RESPONSE message to different sender', to: 2, from: 1 }, ]; const groupedMessage = messages.reduce((acc, curr) => { const node = acc.find(item => item.find((msg) => (msg.from === curr.to && msg.to === curr.from) || (msg.from === curr.from && msg.to === curr.to))); node? node.push(curr): acc.push([curr]); return acc; }, []); console.log(groupedMessage);