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<len;i++) {
traverse(children[i]);
}
callback(currentNode);
})(this._root);
}

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<len;i++) {
if(arr[i].data === data) {
index = i;
}
}
return index;
}

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