工作中常常遇到将后端传过来的数据处理成树形结构的数据,特此记录一下,如有不对的地方,欢迎指出.

情景描述:后端传过来的数据格式:

categoryList:[{
    name:'水果',
    parentId:'0',
    id:'10',
    isLeafe:'0'
    },{
    name:'甜品',
    parentId:'0',
    id:'20',
    isLeafe:'0'
    },{
    name:'文具',
    parentId:'0',
    id:'30',
    isLeafe:'0'
    },{
    name:'香蕉',
    parentId:'10',
    id:'1010',
    isLeafe:'1'
    },{
    name:'菠萝',
    parentId:'10',
    id:'1020',
    isLeafe:'1'
    },
]

希望处理之后的格式为:

categoryList:[{
    name:'水果',
    parentId:'0',
    id:'10',
    isLeafe:'0',
    children:[{
        name:'香蕉',
        parentId:'10',
        id:'1010',
        isLeafe:'1'
        },{
        name:'菠萝',
        parentId:'10',
        id:'1020',
        isLeafe:'1'
        }]
    },{
    name:'甜品',
    parentId:'0',
    id:'20',
    isLeafe:'0'
    },{
    name:'文具',
    parentId:'0',
    id:'30',
    isLeafe:'0'
    },
]

相应的代码实现:

//可以生成多级嵌套的树
let categoryTree = []; 
let list = categoryList.reduce(function(prev, item){
                prev[item.parentId]?prev[item.parentId].push(item):prev[item.parentId] = [item];
                return prev
            },{});

            
for (let key in list) {
    list[key].forEach(function (item) {
    item.children = list[item.id] ? list[item.id] : [];
    });
}

categoryTree = list[0];