数组转树形结构的一种非递归算法.html

<script type="text/javascript">
	let res = [
		{pid: null, id: 1, name: '部门A'},
		{pid: null, id: 2, name: '部门B'},
		{pid: null, id: 3, name: '部门C'},
		{pid: 1, id: 4, name: '部门A'},
		{pid: 4, id: 5, name: '部门A'},
		{pid: 7, id: 6, name: '部门A'},
		{pid: 1, id: 7, name: '部门A'},
		{pid: 3, id: 8, name: '部门A'},
		{pid: 8, id: 9, name: '部门A'},
	];

	// 非递归算法，利用的是js中数组和对象存的是数据的指针（引用）
	// 组装list为树形结构，hash为工具变量

	let list = [];
	let hash = {};

	// 赋值工具变量hash
	for(let i=0; i<res.length; i++){
	    let tmp = res[i];
	    hash[tmp.id] = tmp;
	}

	for(let i=0; i<res.length; i++){
	    let tmp = res[i];

	    // 首层
	    if( tmp.pid === null ){
	    	list.push(tmp);

	    // 非首层在hash中找父级
	    }else{
	        let pNode = hash[tmp.pid];
	        if( pNode ){
	            if( !pNode.children ){
	            	pNode.children = []; // 加children属性
	            }
	            pNode.children.push(tmp);
	        }
	    }
	}

	console.log(list);
</script>

好思路