如果为真，则从map函数返回对象。

Question

只有在检查文档时，我才希望从map函数返回对象。这是我的州结构。

    {
        type: ListOfTypes[Math.floor(Math.random() * ListOfTypes.length)],
        name: ListOfNames[Math.floor(Math.random() * ListOfNames.length)],
        id: nanoid(),
        channels: [
            {
                id: nanoid(),
                Name: ListOfChannels[Math.floor(Math.random() * ListOfChannels.length)],
                Files: [
                    { folder: "Folder", id: nanoid(), documents: [{ doc: "WordDoc1.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc2.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc3.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc4.doc", isChecked: false, id: nanoid() }] },
                    { folder: "Folder", id: nanoid(), documents: [{ doc: "WordDoc1.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc2.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc3.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc4.doc", isChecked: false, id: nanoid() }] },
                    { folder: "Folder", id: nanoid(), documents: [{ doc: "WordDoc1.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc2.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc3.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc4.doc", isChecked: false, id: nanoid() }] },],
            },
            {
                id: nanoid(),
                Name: ListOfChannels[Math.floor(Math.random() * ListOfChannels.length)],
                Files: [
                    { folder: "Folder", id: nanoid(), documents: [{ doc: "WordDoc1.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc2.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc3.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc4.doc", isChecked: false, id: nanoid() }] },
                    { folder: "Folder", id: nanoid(), documents: [{ doc: "WordDoc1.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc2.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc3.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc4.doc", isChecked: false, id: nanoid() }] },
                    { folder: "Folder", id: nanoid(), documents: [{ doc: "WordDoc1.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc2.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc3.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc4.doc", isChecked: false, id: nanoid() }] },
                ],
            },
            {
                id: nanoid(),
                Name: ListOfChannels[Math.floor(Math.random() * ListOfChannels.length)],
                Files: [
                    { folder: "Folder", id: nanoid(), documents: [{ doc: "WordDoc1.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc2.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc3.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc4.doc", isChecked: false, id: nanoid() }] },
                    { folder: "Folder", id: nanoid(), documents: [{ doc: "WordDoc1.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc2.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc3.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc4.doc", isChecked: false, id: nanoid() }] },
                    { folder: "Folder", id: nanoid(), documents: [{ doc: "WordDoc1.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc2.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc3.doc", isChecked: false, id: nanoid() }, { doc: "WordDoc4.doc", isChecked: false, id: nanoid() }] },
                ],
            }
        ]
    }

我试图通过状态数组进行映射，但是我使用它得到了一个带有非必要数组的对象。

const handleMoveAll = () => {

    const CheckedDocuments = List.map( (connection: any) => (connection.id == connectionId) &&
        connection.channels.map( (channel: any) => (channel.id == channelId) &&
            channel.Files.map( (file: any) =>
                file.documents.map( (doc: any) => doc.isChecked && 
                doc
                ))

        )
    )

    console.log(CheckedDocuments)
}

是否有更好的方法循环遍历Files数组，检查所检查的文档并在单个数组中返回它们？

Answer 1

感谢HagaiHarari和oakar。

const handleMoveAll = () => {

        const CheckedDocuments = List.flatMap((connection: any) => (connection.id == connectionId) ?
            connection.channels.flatMap((channel: any) => (channel.id == channelId) ?
                channel.Files.flatMap( (file: any) =>
                    file.documents.filter( (doc: any) => { if(doc.isChecked) return doc }
                    ))
                : []
            )
            : []
        )

        console.log(CheckedDocuments)
    }