php正则替换中变量的指定字符

<?php
$str = preg_quote('(银子)');
$txt = '我的呢称(银子)';
echo preg_replace("/($str)/","<span style='color:#f00;'>$1</span>",$txt);
?>

<?php
$str = quotemeta('(银子)');
$txt = '我的呢称(银子)';
echo preg_replace("/($str)/","<span style='color:#f00;'>$1</span>",$txt);
?>

$text  = “foobar123fooabcbar”;

$text = preg_replace(“/foo(?=bar)/”, “***”, $text);

$text  = “foobar123fooabcbar”;

$text = preg_replace(“/(?<=bar)123/”, “***”, $text);

$text  = “foobar123fooabcbar”;

$text = preg_replace(“/foo(?!bar)/”, “***”, $text);

$text  = “foobar123fooabcbar”;

$text = preg_replace(“/(?<!foo)bar/”, “***”, $text);

CREATE TABLE messages
(
msg_id INT PRIMARY KEY AUTO_INCREMENT,
message VARCHAR(150)
);

<script type="text/javascript" src="http://ajax.googleapis.com/
ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function()
{

function loading_show()
{
$('#loading').html("<img src='images/loading.gif'/>").fadeIn('fast');
}

function loading_hide()
{
$('#loading').fadeOut();
}

function loadData(page)
{
loading_show();
$.ajax
({
type: "POST",
url: "load_data.php",
data: "page="+page,
success: function(msg)
{
$("#container").ajaxComplete(function(event, request, settings)
{
loading_hide();
$("#container").html(msg);
});
}
});
}
loadData(1); // For first time page load default results
$('#container .pagination li.active').live('click',function(){
var page = $(this).attr('p');
loadData(page);
});
});

</script>

<?php
if($_POST['page'])
{
$page = $_POST['page'];
$cur_page = $page;
$page -= 1;
$per_page = 15; // Per page records
$previous_btn = true;
$next_btn = true;
$first_btn = true;
$last_btn = true;
$start = $page * $per_page;
include"db.php";
$query_pag_data = "SELECT msg_id,message from messages LIMIT $start, $per_page";
$result_pag_data = mysql_query($query_pag_data) or die('MySql Error' . mysql_error());
$msg = "";
while ($row = mysql_fetch_array($result_pag_data))
{
$htmlmsg=htmlentities($row['message']); //HTML entries filter
$msg .= "<li><b>" . $row['msg_id'] . "</b> " . $htmlmsg . "</li>";
}
$msg = "<div class='data'><ul>" . $msg . "</ul></div>"; // Content for Data
/* -----Total count--- */
$query_pag_num = "SELECT COUNT(*) AS count FROM messages"; // Total records
$result_pag_num = mysql_query($query_pag_num);
$row = mysql_fetch_array($result_pag_num);
$count = $row['count'];
$no_of_paginations = ceil($count / $per_page);
/* -----Calculating the starting and endign values for the loop----- */

//Some Code. Available in download script

}
?>

$a = array(1 => 'a', 'b', 'c');
$b = array(1 => 'aa', 2, 'c');
$union = array_merge($a, $b);
$plus = $a + $b;
print_r($union);
print_r($plus);
结果依次为：
Array
{
[0]=> a
[1]=> b
[2]=> c
[3]=> aa
[4]=> 2
[5]=> c
}
Array
(
[1] => a
[2] => b
[3] => c
)

$a2 = array('str' => 'a', 'b', 'c');
$b2 = array('str' => 'aa', 2, 'c');
$union2 = array_merge($a2, $b2);
$plus2 = $a2 + $b2;
print_r($union2);
print_r($plus2);

结果依次为：

Array
(
[str] => aa
[0] => b
[1] => c
[2] => 2
[3] => c
)
Array
(
[str] => a
[0] => b
[1] => c
)

$intersection2 = array_intersect(array_map('strtolower',$a), array_map('strtolower',$b));
print_r($intersection);
print_r($intersection2);

$old = array('jpg','png','gif','bmp');
$new = array('JPG','txt','docx','bmp');
$difference = array_diff($old, $new);

$difference = array_diff(array_map('strtolower',$old), array_map('strtolower',$new));

<?php
$a =array(100,80,50,10,0);
$b = array("c","f","q","e","z");
array_multisort($a,$b);
var_dump($a);
var_dump($b);
?>
运行结果：
array(5) { [0]=> int(0) [1]=> int(10) [2]=> int(50) [3]=> int(80) [4]=> int(100) }
array(5) { [0]=> string(1) “z” [1]=> string(1) “e” [2]=> string(1) “q” [3]=> string(1) “f” [4]=> string(1) “c” }

<?php

/**
 * Validator for Login.
 */
final class LoginValidator {

    private function __construct() {
       
    }

    /**
     * Validate the given username and password.
     * @param $username and $password to be validated
     * @return array array of {@link Error} s
     */
    public static function validate($username, $password) {
        $errors = array();
        $username = trim($username);
        if (!$username) {
            $errors[] = new Error('username', '用户名不能为空。');
        } elseif (strlen($username)<3) {
            $errors[] = new Error('username', '用户名长度不能小于3个字符。');
        } elseif (strlen($username)>30) {
            $errors[] = new Error('username', '用户名长度不能超过30个字符。');
        } elseif (!preg_match('/^[A-Za-z]+$/',substr($username, 0, 1))) {
            $errors[] = new Error('username', '用户名必须以字母开头。');
        } elseif (!preg_match('/^[A-Za-z0-9_]+$/', $username)) {
            $errors[] = new Error('username', '用户名只能是字母、数字以及下划线( _ )的组合。');
        } elseif (!trim($password)) {
            $errors[] = new Error('password', '密码不能为空。');
        } else {
            // check whether use exists or not
            $dao = new UserDao();
            $user = $dao->findByName($username);

            if ($user) {
                if (!($user->getPassword() == sha1($user->getSalt() . $password))) {
                    $errors[] = new Error('password', '用户名或密码错误。');
                }
            } else {
                $errors[] = new Error('username', '用户名不存在。');
            }
        }
        return $errors;
    }
}

?>

$username = null;
$password = null;

$msg = "";

if (isset($_POST['username']) && isset($_POST['password'])) {
    $username = addslashes(trim(stripslashes($_POST ['username'])));
    $password = addslashes(trim(stripslashes($_POST ['password'])));
    // validate
    $errors = LoginValidator::validate($username, $password);
   
    if (empty($errors)) {
        // save the latest ip or login time into database, then processing page forwarding
        $dao = new UserDao();
        $user = $dao->findByName($username);
        $last_login_ip = Utils::getIpAddress();
        $user->setLastLoginIp($last_login_ip);
        $now = new DateTime();
        $user->setLastLoginTime($now);
        $dao->save($user);
        UserLogin::setUserInfo($user);
        Flash::addFlash('登录成功！');
        Utils::redirect('welcome');
    }
   
    foreach ($errors as $e) {
        $msg .= $e->getMessage()."<br>";
    }