地区数据整理

var oldArr = [
    { province: '广东省', city: '广州市', district: '天河区' },
    { province: '广东省', city: '广州市', district: '白云区' },
    { province: '广东省', city: '东莞市', district: '常平镇' },
    { province: '广东省', city: '东莞市', district: '虎门镇' },
    { province: '广东省', city: '东莞市', district: '长安镇' },
    { province: '广西省', city: '南宁市', district: '兴宁区' },
    { province: '广西省', city: '南宁市', district: '江南区' },
    { province: '海南省', city: '海口市', district: '琼山区' },
    { province: '海南省', city: '三亚市', district: '海棠区' },
    { province: '海南省', city: '三沙市', district: '南沙区' },
]
var newArr = []
var item = {}   // 区
var item1 = {}  // 市
for (let i = 0; i < oldArr.length; i++) {
    // 没有这个省的
    if (!item[oldArr[i].province]) {
        newArr.push({
            name: oldArr[i].province,
            children: [
                {
                    name: oldArr[i].city,
                    children: [
                        { name: oldArr[i].district }
                    ],
                }
            ]
        })
        item[oldArr[i].province] = oldArr[i].province
        item1[oldArr[i].city] = oldArr[i].city
    } else {
        // 遍历newArr，看看这个省的位置
        for (let j = 0; j < newArr.length; j++) {
            if (newArr[j].name == item[oldArr[i].province]) {
                // 这个省没有这个市，就往省的children添加市
                if (!item1[oldArr[i].city]) {
                    if (newArr[j].name == item[oldArr[i].province]) {
                        newArr[j].children.push({
                            name: oldArr[i].city,
                            children: [
                                {
                                    name: oldArr[i].district,
                                }
                            ],
                        })
                        item1[oldArr[i].city] = oldArr[i].city
                    }
                } else {
                    // 有这个省有这个市了就往市里面的children添加区
                    for (let x = 0; x < newArr[j].children.length; x++) {
                        if (newArr[j].children[x].name == item1[oldArr[i].city]) {
                            newArr[j].children[x].children.push({
                                name: oldArr[i].district,
                            })
                        }
                    }
                }
            }

        }
    }
}
console.log(newArr)
console.log('item', item)
console.log('item1', item1)