Javascript实现树结构

树节点属性  Node

•    data：节点值
•    parent ：指向节点的父节点
•   children：指向节点的孩子节点

Tree 属性与方法

•    _root  ：树的根节点
•   traverseDF(callback) ：深度遍历
•  traverseBF(callback)：广度遍历

树的实现

树节点定义：

  function Node(data) {
			this.data = data;
			this.parent = null;
			this.children = [];
		}

树的构造函数：

 function Tree(data) {
			var node = new Node(data);
			this._root = node;
		}

树的方法

• traverseDF(callback)
• traverseBF(callback)
• contains(data, traversal)
• add(child, parent)
• remove(node, parent)

1 of 5: traverseDF(callback)

    Tree.prototype.traverseDF = function(callback) {
			(function traverse(currentNode) {
				var i,len;
				var children = currentNode.children;
				for(i=0,len = children.length;i

2 of 5: traverseBF(callback)

   Tree.prototype.traverseBF = function(callback) {
			var queue = [],
			    i,
			    len;
			queue.push(this._root);
			while(queue.length) {
				var cur = queue.shift();
				callback(cur);
				for(i=0,len = cur.children.length; i < len;i++) {
					queue.push(cur.children[i]);
				}
			}
		}

3 of 5: contains(callback, traversal)

  Tree.prototype.contains = function(callback, traversal) {
			traversal.call(this, callback);
		}

例如：

  tree.contains(function(node){
                if (node.data === 'two') {
                   console.log(node);
                }
           }, tree.traverseBF);

4 of 5: add(data, toData, traversal)

   Tree.prototype.add = function(data, toData, traversal) {
			var child = new Node(data),
			    parent = null,
			    callback = function(node) {
			    	if(node.data === toData) {
			    		parent = node;
			    	}
			    }
			this.contains(callback, traversal);
			if(parent) {
				parent.children.push(child);
				child.parent = parent;
			}else {
				throw new Error('cannot add node to an unexist parent');
			}
		}

5 of 5:  remove(data, fromData, traversal)

    Tree.prototype.remove = function(data, fromData, traversal) {
			var tree = this,
				parent = null,
				childToRemove = null,
				i,len,children,
				index;

			var	callback = function(node) {
					if(node.data === fromData) {
						parent = node;
					}
				}
			this.contains(callback, traversal);
			if(parent) {
				index = findIndex(parent.children, data);
				console.log(index);
				if(index === undefined) {
					throw new Error("Node to remove does not exist");
				}else {
					childToRemove = parent.children.splice(index, 1);
				}
			}
			console.log(childToRemove);
			return childToRemove;
		}

   function findIndex(arr, data){
			var i=0,
				len = arr.length,
				index;
			for(;i

例如：

  var tree = new Tree('one');

		tree._root.children.push(new Node('two'));
		tree._root.children[0].parent = tree;
		tree._root.children.push(new Node('three'));
		tree._root.children[1].parent = tree;

		tree._root.children[0].children.push(new Node('four'));
		tree._root.children[0].children[0].parent = tree._root.children[0];
		tree._root.children[0].children.push(new Node('five'));
		tree._root.children[0].children[1].parent = tree._root.children[0];

		tree._root.children[1].children.push(new Node('six'));
		tree._root.children[1].children[0].parent = tree._root.children[1];
		tree._root.children[1].children.push(new Node('serven'));
		tree._root.children[1].children[1].parent = tree._root.children[1];
		// tree.traverseBF(function(node) {
		// 	console.log(node.data);
		// });
		tree.contains(function(node) {
			if(node.data === 'two') {
				console.log(node);
			}
		}, tree.traverseBF);
		tree.add("eight","four", tree.traverseBF);
		var remove =  tree.remove("two", "one", tree.traverseBF);
		tree.traverseBF(function(node) {
			console.log(node.data);
		});

原文地址：http://code.tutsplus.com/articles/data-structures-with-javascript-tree--cms-23393