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    ▪基于PHP+Ajax实现表单验证的详解       一，利用键盘响应，在不刷新本页面的情况下验证表单输入是否合法用户通过onkeydown和onkeyup事件来触发响应事件。使用方法和onclick事件类似。onkeydown表示当键盘上的键被按下时触发，onkeyup.........

    ▪PHP Class&Object -- 解析PHP实现二叉树       二叉树及其变体是数据结构家族里的重要组成部分。最为链表的一种变体，二叉树最适合处理需要一特定次序快速组织和检索的数据。 代码如下:<?php// Define a class to implement a binary treeclass .........

    ▪PHP Class&Object -- PHP 自排序二叉树的深入解析       在节点之间再应用一些排序逻辑，二叉树就能提供出色的组织方式。对于每个节点，都让满足所有特定条件的元素都位于左节点及其子节点。在插入新元素时，我们需要从树的第一个节 点(.........

代码如下:

<script type="text/javascript">
   ...
   function refer(){
   ...
   }
</script>
<input type="text" onkeydown="refer()"/> 

代码如下:

window.onload = function(){
 $('regname').onkeydown = function (){
  name = $('regname').value;
 }
}

代码如下:

function $(id){
 return document.getElementById(id);
}
window.onload事件，表示当前窗口被载入时触发。function(){...}表示当前页面被载入时所要进行的操作。
window.onload = function(){
 ...
}

代码如下:

$('regname').focus();
var cname1,cname2,cpwd1,cpwd2;  //声明了5个变量，表示要检测的5项数据chkreg()函数是每一次触发键盘事件后都要调用的，该函数判断5个变量的值，只有当所有变量都为"yes"时，注册按钮才会被激活。
function chkreg(){
 if((cname1 == 'yes') && (cname2 == 'yes') && (cpwd1 == 'yes') && (cpwd2 == 'yes')){
  $('regbtn').disabled = false;
 }else{
  $('regbtn').disabled = true;
 }
}

代码如下:

$('regname').onkeyup = function (){
 name = $('regname').value;  //获取注册名称
 cname2 = '';
 if(name.match(/^[a-zA-Z_]*/) == ''){
  $('namediv').innerHTML = '<font color=red>必须以字母或下划线开头</font>';
  cname1 = '';
 }else if(name.length <= 3){
  $('namediv').innerHTML = '<font color=red>注册名称必须大于3位</font>';
  cname1 = '';
 }else{
  $('namediv').innerHTML = '<font color=green>注册名称符合标准</font>';
  cname1 = 'yes';
 }
 chkreg(); //调用chkreg()函数，判断5个变量是否正确
}

代码如下:

$('regname').onblur = function(){
 name = $('regname').value;  //获取注册名称
 if(cname1 == 'yes'){ //当用户名称的格式输入合格后才进行这一步
  xmlhttp.open('get','chkname.php?name='+name,true);  //open()创建XMLHttpRequest初始化连接，Ajax创建新的请求
  xmlhttp.onreadystatechange = function(){  //当指定XMLHttpRequest为异步传输时(false),发生任何状态的变化，该对象都会调用onreadystatechange所指定的函数
   if(xmlhttp.readyState == 4){  //XMLHttpRequest处理状态，4表示处理完毕
    if(xmlhttp.status == 200){ //服务器响应的HTTP代码，200表示正常
     var msg = xmlhttp.responseText;  //获取响应页的内容
     if(msg == '1'){  //chkname.php页面查找数据库，数据库没有该用户返回1
      $('namediv').innerHTML="<font color=green>恭喜您，该用户名可以使用!</font>";
      cname2 = 'yes';
     }else if(msg == '2'){ //数据库存在该用户返回0
      $('namediv').innerHTML="<font color=red>用户名被占用！</font>";
      cname2 = '';
     }else{
      $('namediv').innerHTML="<font color=red>"+msg+"</font>";
      cname2 = '';
     }
    }
   }
  }
  xmlhttp.send(null);
  chkreg(); //检测是否激活注册按钮
 }
}

代码如下:

$('regpwd1').onkeyup = function(){
 pwd = $('regpwd1').value;
 pwd2 = $('regpwd2').value;
 if(pwd.length < 6){
  $('pwddiv1').innerHTML = '<font color=red>密码长度最少需要6位</font>';
  cpwd1 = '';
 }else if(pwd.length >= 6 && pwd.length < 12){
  $('pwddiv1').innerHTML = '<font color=green>密码符合要求。密码强度：弱</font>';
  cpwd1 = 'yes';
 }else if((pwd.match(/^[0-9]*$/)!=null) || (pwd.match(/^[a-zA-Z]*$/) != null )){
  $('pwddiv1').innerHTML = '<font color=green>密码符合要求。密码强度：中</font>';
  cpwd1 = 'yes';
 }else{
  $('pwddiv1').innerHTML = '<font color=green>密码符合要求。密码强度：高</font>';
  cpwd1 = 'yes';
 }
 if(pwd2 != '' && pwd != pwd2){
  $('pwddiv2').innerHTML = '<font color=red>两次密码不一致!</font>';
  cpwd2 = '';
 }else if(pwd2 != '' && pwd == pwd2){
  $('pwddiv2').innerHTML = '<font color=green>密码输入正确</font>';
  cpwd2 = 'yes';
 }
 chkreg();
}

代码如下:

$('regpwd2').onkeyup = function(){
 pwd1 = $('regpwd1').value;
 pwd2 = $('regpwd2').value;
 if(pwd1 != pwd2){
  $('pwddiv2').innerHTML = '<font color=red>两次密码不一致!</font>';
  cpwd2 = '';
 }else{
  $('pwddiv2').innerHTML = '<font color=green>密码输入正确</font>';
  cpwd2 = 'yes';
 }
 chkreg();
}

代码如下:

$('morebtn').onclick = function(){
 if($('morediv').style.display == ''){
  $('morediv').style.display = 'none';
 }else{
  $('morediv').style.display = '';
 }
}

代码如下:

$('email').onkeyup = function(){
 emailreg = /^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$/;
 $('email').value.match(emailreg);
 if($('email').value.match(emailreg) == null){
  $('emaildiv').innerHTML = '<font color=red>错误的email格式</font>';
  cemail = '';
 }else{
  $('emaildiv').innerHTML = '<font color=green>输入正确</font>';
  cemail = 'yes';

 }
 chkreg();
}

代码如下:

<?php
session_start();
include_once "conn/conn.php";
$reback = '0';
$sql = "select * from tb_member where name='".$_GET['name']."'";
$num = $conne->getRowsNum($sql);
if($num == 1){
 $reback = '2';
}else if($num == 0){
 $reback = '1';
}else{
 $reback = $conne->msg_error();
}
echo $reback;
?>

代码如下:

// JavaScript Document
var xmlhttp = false;
if (window.XMLHttpRequest) {          //Mozilla、Safari等浏览器
 xmlhttp = new XMLHttpRequest();
}
else if (window.ActiveXObject) {         //IE浏览器
 try {
  xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
 } catch (e) {
  try {
   xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    } catch (e) {}
 }
}

代码如下:

<?php
// Define a class to implement a binary tree
class Binary_Tree_Node {
    // Define the variable to hold our data:
    public $data;
    // And a variable to hold the left and right objects:
    public $left;
    public $right;

    // A constructor method that allows for data to be passed in
    public function __construct($d = NULL) {
        $this->data = $d;
    }

    // Traverse the tree, left to right, in pre-order, returning an array
    // Preorder means that each node's value preceeds its children.
    public function traversePreorder() {
        // Prep some variables.
        $l = array();
        $r = array();
        // Read in the left and right children appropriately traversed:
        if ($this->left) { $l = $this->left->traversePreorder(); }
        if ($this->right) { $r = $this->right->traversePreorder(); }

        // Return a merged array of the current value, left, and right:
        return array_merge(array($this->data), $l, $r);
    }
    // Traverse the tree, left to right, in postorder, returning an array
    // Postorder means that each node's value follows its children.
    public function traversePostorder() {
        // Prep some variables.
        $l = array();
        $r = array();
        // Read in the left and right children appropriately traversed:
        if ($this->left) { $l = $this->left->traversePostorder(); }
        if ($this->right) { $r = $this->right->traversePostorder(); }

        // Return a merged array of the current value, left, and right:
        return array_merge($l, $r, array($this->data));
    }
    // Traverse the tree, left to right, in-order, returning an array.
    // In-order means that values are ordered as left children, then the
    //  node value, then the right children.
    public function traverseInorder() {
        // Prep some variables.
        $l = array();
        $r = array();
        // Read in the left and right children appropriately traversed:
        if ($this->left) { $l = $this->left->traverseInorder(); }
        if ($this->right) { $r = $this->right->traverseInorder(); }

        // Return a merged array of the current value, left, and right:
        return array_merge($l, array($this->data), $r);
    }
}
// Let's create a binary tree that will equal the following:    3
//                                                             / /     
//                                                            h   9     
//                                                               / /    
// Create the tree:                                             6   a   
$tree = new Binary_Tree_Node(3);
$tree->left = new Binary_Tree_Node('h');
$tree->right = new Binary_Tree_Node(9);
$tree->right->left = new Binary_Tree_Node(6);
$tree->right->right = new Binary_Tree_Node('a');
// Now traverse this tree in all possible orders and display the results:
// Pre-order: 3, h, 9, 6, a
echo '<p>', implode(', ', $tree->traversePreorder()), '</p>';
// Post-order: h, 9, 6, a, 3
echo '<p>', implode(', ', $tree->traversePostorder()), '</p>';
// In-order: h, 3, 6, 9, a
echo '<p>', implode(', ', $tree->traverseInorder()), '</p>';
?>

代码如下:

<?php
ob_start();
// Here we need to include the binary tree class
Class Binary_Tree_Node() {
   // You can find the details at
}
ob_end_clean();
// Define a class to implement self sorting binary tree
class Sorting_Tree {
    // Define the variable to hold our tree:
    public $tree;
    // We need a method that will allow for inserts that automatically place
    // themselves in the proper order in the tree
    public function insert($val) {
        // Handle the first case:
        if (!(isset($this->tree))) {
            $this->tree = new Binary_Tree_Node($val);
        } else {
            // In all other cases:
            // Start a pointer that looks at the current tree top:
            $pointer = $this->tree;
            // Iteratively search the tree for the right place:
            for(;;) {
                // If this value is less than, or equal to the current data:
                if ($val <= $pointer->data) {
                    // We are looking to the left ... If the child exists:
                    if ($pointer->left) {
                        // Traverse deeper:
                        $pointer = $pointer->left;
                    } else {
                        // Found the new spot: insert the new element here:
                        $pointer->left = new Binary_Tree_Node($val);
                        break;
                    }
                } else {
                    // We are looking to the right ... If the child exists:
                    if ($pointer->right) {
                        // Traverse deeper:
                        $pointer = $pointer->right;
                    } else {
                        // Found the new spot: insert the new element here:
                        $pointer->right = new Binary_Tree_Node($val);
                        break;
                    }
                }
            }
        }
    }

    // Now create a method to return the sorted values of this tree.
    // All it entails is using the in-order traversal, which will now
    // give us the proper sorted order.
    public function returnSorted() {
        return $this->tree->traverseInorder();
    }
}
// Declare a new sorting tree:
$sort_as_you_go = new Sorting_Tree();
// Let's randomly create 20 numbers, inserting them as we go:
for ($i = 0; $i < 20; $i++) {
    $sort_as_you_go->insert(rand(1,100));
}
// Now echo the tree out, using in-order traversal, and it will be sorted:
// Example: 1, 2, 11, 18, 22, 26, 32, 32, 34, 43, 46, 47, 47, 53, 60, 71,
//   75, 84, 86, 90
echo '<p>', implode(', ', $sort_as_you_go->returnSorted()), '</p>';
?>