将input数据格式转换为output数据格式
let input = [{
id: 1, val: '学校', parentId: null
},{
id: 2, val: '班级1', parentId: 1
},{
id: 3, val: '班级2', parentId: 1
},{
id: 4, val: '学生1', parentId: 2
},{
id: 5, val: '学生2', parentId: 3
},{
id: 6, val: '学生3', parentId: 3
}]
let output = {
id: 1,
val: '学校',
children: [{
id: 2,
val: '班级1',
children: [
{
id: 4,
val: '学生1',
children: []
}
]
}, {
id: 3,
val: '班级2',
children: [
{
id: 5,
val: '学生2',
children: []
},{
id: 6,
val: '学生3',
children: []
}
]
}]
}
实现方式
function arrToTree(input){
let { id,val } = input.find(item => item.parentId === null)
let output = {
id,val
}
let toTree = (id,input) => {
let children = []
for(let i = 0;i < input.length;i++){
let item = input[i]
if(id == item.parentId){
children.push({
id:item.id,
val:item.val,
children:toTree(item.id,input)
})
}
}
return children
}
output.children = toTree(id,input)
return output
}