• 一维数组和二维数组相互转换
• 判断数组内容是否相同
• 数组的交集
• 遍历树

[toc]

数组相关

一维数组和二维数组相互转换

/* 一维数组转二位数组 */
function oneDimensionalToTwo(array, length) {
    if(!array.length || !length || array.length < length) return array
    const newArr = []
    let j = -1
    for (let i = 0; i < array.length; i++) {
        if(i%length === 0) {
            j++
            newArr[j] = []
        }
        newArr[j].push(array[i])
    }
    return newArr
}

/* 一维数组转二位数组 */
// 参考 js 笔记中的 flat 方法

判断数组内容是否相同

当前只针对简单的基础类型数组值判断

function equalArray (arr1, arr2) {
    if(!(arr1 instanceof Array) || !(arr2 instanceof Array)) return false
    if (arr1.length !== arr2.length) return false
    for (let i = 0; i < arr1.length; i++) { 
        if(!arr2.includes(arr1[i])) return false
    }
    return true
}

function equalObjectArray(arr1, arr2) {
    if (!(arr1 instanceof Array) || !(arr2 instanceof Array)) return false
    if (arr1.length !== arr2.length) return false

    for (let i = 0; i < arr1.length; i++) {
        /* equalObject 在 object.md */
        if (!arr2.some(item => equalObject(item, arr1[i]))) {
            return false
        }
    }

    return true
}

数组的交集

/**
 * @des 获取数组的交集
 */
export const arrayIntersection = (r1, r2) => {
    const a = [...new Set(r1)]
    const b = [...new Set(r2)]

    return a.filter(v => b.includes(v))
}

遍历树

const tree = [
    {
        id: 1,
        label: '一级 1',
        children: [{
            id: 4,
            label: '二级 1-1',
            children: [{
                id: 9,
                label: '三级 1-1-1'
            }, {
                id: 10,
                label: '三级 1-1-2'
            }]
        }]
    }, {
        id: 2,
        label: '一级 2',
        children: [{
            id: 5,
            label: '二级 2-1'
        }, {
            id: 6,
            label: '二级 2-2'
        }]
    }, {
        id: 3,
        label: '一级 3',
        children: [{
            id: 7,
            label: '二级 3-1'
        }, {
            id: 8,
            label: '二级 3-2'
        }]
    }]

const loopTree = (data, level) => {
    const tempArr = [];
    data.forEach(v => {
        const tempObj = {}
        tempObj.id = v.id
        tempObj.label = `new ${v.label}-level:${level}`
        if (v.children && v.children.length) {
            tempObj.list = loopTree(v.children, level+1)
        }
        tempArr.push(tempObj)
    })
    return tempArr
}

console.log(loopTree(tree, 0));