概念描述

• 深度优先遍历（遍历+递归）、广度优先遍历（队列）
• 实现树转换为数组

代码实现

/**
* @description: treeToArr
* @author: huen2015
*/

interface IArrayData {
    id: number,
    name: string,
    parentId: number,
    children?: IArrayData[]
}

interface ITreeData extends IArrayData {
    children?: IArrayData[]
}

/**
* @description: 深度优先遍历（遍历 + 递归）
* @param: tree: ITreeData => IArrayData[]
* @author: huen2015
*/
function depthFirstTreeToArr(tree: ITreeData): IArrayData[] {
    const result: IArrayData[] = []
    const { id, name, parentId, children = [] } = tree
    if (id) {
        result.push({ id, name, parentId })
        if (children.length) {
            children.forEach((item: ITreeData) => {
                result.push(...depthFirstTreeToArr(item))
            })
        }
    }
    return result
}

/**
* @description: 广度优先遍历（队列）
* @param: 
* @author: huen2015
*/
function breadthFirstTreeToArr(tree: ITreeData): IArrayData[] {
    const result: IArrayData[] = []
    const queue: IArrayData[] = []
    queue.push(tree)

    while (queue.length) {
        const treeItem = queue.shift()
        if (treeItem) {
            const { id, name, parentId, children = [] } = treeItem
            result.push({ id, name, parentId })
            if (children.length) {
                children.forEach((item: ITreeData) => {
                    queue.push(item)
                })
            }
        }
    }

    return result
}

const treeToArrData: ITreeData = {
    id: 1,
    name: '湖北省',
    parentId: 0,
    children: [
        {
            id: 2,
            name: '武汉市',
            parentId: 1,
            children: [
                { id: 4, name: '武昌区', parentId: 2 },
                { id: 5, name: '江岸区', parentId: 2 }
            ]
        },
        {
            id: 3,
            name: '黄冈市',
            parentId: 1,
            children: [{ id: 6, name: '黄州区', parentId: 3 }]
        }
    ]
}

const depthFirstTreeToArrResult = depthFirstTreeToArr(treeToArrData)
console.log('depthFirstTreeToArrResult', depthFirstTreeToArrResult)
const breadthFirstTreeToArrResult = breadthFirstTreeToArr(treeToArrData)
console.log('breadthFirstTreeToArrResult', breadthFirstTreeToArrResult)

代码演示仓库