Pure JavaScript implements the traversal of a DOM tree

traversal of a two-fork DOM Tree [JavaScript]View Plain copy function tree () {var Node = function (key) {this.key = key;               This.left = null;         This.right = null;   Root =null; } Pre-sequence traversal

<code style= "font-family: ' Source code Pro ', Consolas, Menlo, Monaco, ' Courier New ', monospace; Font-size:1em; Color:inherit; padding:0px; White-space:inherit; Background:none; " > First access the root node, then traverse the left subtree, and finally traverse the right subtree </code>

[JavaScript]  View Plain  copy   Tree.prototype.preordertraverse = function (callback) {       preorder (root, callback);  }   var preOrder =  function (node,callback) {       if (node !== null) {            callback (node.key);            preorder (node.left, callback);            Preorder (node.right, callback);       }  }       

<code style= "font-family: ' Source code Pro ', Consolas, Menlo, Monaco, ' Courier New ', monospace; Font-size:1em; Color:inherit; padding:0px; White-space:inherit; Background:none; " > modified to Dom two fork tree:</code>

[JavaScript] view plain copy var preorder = function (Node,callback) {Callback (node);       if (node.firstelementchild) {///First, determine if the child element node exists This.preorder (node.firstelementchild,callback);       } if (Node.lastelementchild) {this.preorder (node.lastelementchild,callback); }   };

in-sequence traversal

<code style= "font-family: ' Source code Pro ', Consolas, Menlo, Monaco, ' Courier New ', monospace; Font-size:1em; Color:inherit; padding:0px; White-space:inherit; Background:none; " > First traverses the left subtree, then accesses the root node, and finally traverses the right subtree. </code>

[JavaScript]View plain Copy Tree.prototype.inOrderTraverse = function (callback) {inorder (root, callback); var inorder = function (node,callback) {if (node!== null) {