札记 PHP/JS/jQuery/MySQL/CSS/正则/Apache

PHP:

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1、Fatal error: Allowed memory size of 8388608 bytes exhausted
解决：
  方法一：修改php.inimemory_limit = 8M中的8M至合适值；（此方法设置发现失效的话请检查phpinfo定位好php.ini位置重新修改）
  方法二：在程序文件开头加入ini_set("memory_limit","32M");  //32M按需调节

2、cookie子域名共享
bool setcookie ( string $name [, string $value [, int $expire = 0 [, string $path [, string $domain [, bool $secure = false [, bool $httponly = false ]]]]]] )

为了使Cookie在子域名也能够生效，$domain须设置成：'.domain.com'，
如博客园的设置成：'.cnblogs.com'即可。

3、关于echo
<?php
$conn = '__';
echo 'abc';                        //正确
echo "abc";                        //正确
echo ('abc');                      //正确
echo ("abc");                      //正确
echo 'abc'.$conn.'def';            //正确
echo 'abc',$conn,'def';            //正确

// echo ('abc',$conn,'def');       //错误

4、关于ini文件解析
$version = phpversion();
if ($version >= '5.3.1')
{
    $contents = file_get_contents($filename);
    $contents = str_replace('_QQ_', '"\""', $contents);
    $strings = @parse_ini_string($contents);
}
else
{
    $strings = @parse_ini_file($filename);

    if ($version == '5.3.0' && is_array($strings))
    {
        foreach ($strings as $key => $string)
        {
            $strings[$key] = str_replace('_QQ_', '"', $string);
        }
    }
}

@example >=5.3.1
$contents = 'COM_USERS_REGISTER_REQUIRED="<strong class="_QQ_"red"_QQ_">*</strong> Required field"';
var_dump(str_replace('_QQ_', '"\""', $contents),parse_ini_string(str_replace('_QQ_', '"\""', $contents)));
    
/* 
    string(85) "COM_USERS_REGISTER_REQUIRED="<strong class=""\"""red""\""">*</strong> Required field""
    array(1) {
      ["COM_USERS_REGISTER_REQUIRED"]=>
      string(45) "<strong class="red">*</strong> Required field"
    } 
*/

5、解析object成string
/**
 * Converts an object into a php class string.
 * - NOTE: Only one depth level is supported.
 *
 * @param   object  $object  Data Source Object
 * @param   array   $params  Parameters used by the formatter
 *
 * @return  string  Config class formatted string
 *
 * @since   11.1
 */
public function objectToString($object, $params = array())
{
    // Build the object variables string
    $vars = '';
    foreach (get_object_vars($object) as $k => $v)
    {
        if (is_scalar($v))
        {
            $vars .= "\tpublic $" . $k . " = '" . addcslashes($v, '\\\'') . "';\n";
        }
        elseif (is_array($v) || is_object($v))
        {
            $vars .= "\tpublic $" . $k . " = " . $this->getArrayString((array) $v) . ";\n";
        }
    }

    $str = "<?php\nclass " . $params['class'] . " {\n";
    $str .= $vars;
    $str .= "}";

    // Use the closing tag if it not set to false in parameters.
    if (!isset($params['closingtag']) || $params['closingtag'] !== false)
    {
        $str .= "\n?>";
    }

    return $str;
}
/**
 * Method to get an array as an exported string.
 *
 * @param   array  $a  The array to get as a string.
 *
 * @return  array
 *
 * @since   11.1
 */
protected function getArrayString($a)
{
    $s = 'array(';
    $i = 0;
    foreach ($a as $k => $v)
    {
        $s .= ($i) ? ', ' : '';
        $s .= '"' . $k . '" => ';
        if (is_array($v) || is_object($v))
        {
            $s .= $this->getArrayString((array) $v);
        }
        else
        {
            $s .= '"' . addslashes($v) . '"';
        }
        $i++;
    }
    $s .= ')';
    return $s;
}

 6、多维数组排序
 1 <?php
//多维数组按某一维进行排序
$data[] = array('volume' => 67, 'edition' => 2);
$data[] = array('volume' => 86, 'edition' => 1);
$data[] = array('volume' => 85, 'edition' => 6);
$data[] = array('volume' => 98, 'edition' => 2);
$data[] = array('volume' => 86, 'edition' => 6);
$data[] = array('volume' => 67, 'edition' => 7);
// 取得列的列表
foreach ($data as $key => $row) {
    $volume[$key]  = $row['volume'];
    $edition[$key] = $row['edition'];
}

// 将数据根据 volume 降序排列，根据 edition 升序排列
// 把 $data 作为最后一个参数，以通用键排序
array_multisort($volume, SORT_DESC, $edition, SORT_ASC, $data);
echo '<pre>';
var_dump($data);
?> 

7、嵌套div解析
<?php
    /**
     * 模式修饰符s，可使得.能匹配包括换行在内的任意字符
     * 模式修饰符i，不区分大小写匹配     
     * (?!<div.*?>.*<div.*?</div>) 负向预查排除<div中间还带<div的情况
     * <div.*?>(.*?)</div> 每次匹配一个中间不含<div的字符串
     */
    $str = '<div class="a">aaaa<div>
    1111</div><div>
    2222<div>3333
    </div></div>bbbb</div>';
    $str = '<div class="a">1111<div>2222</div>3333</div><div class="a">4444<div>5555</div>6666</div><div class="a">7777<div>8888</div><div>9999</div>aaaa</div>';
    $str = '<div class="a">aaaa<div>1111</div><div><span>2222</span></div>bbbb</div>';

    $results = array();
    while(preg_match('#(?!<div.*?>.*<div.*?</div>)<div.*?>(.*?)</div>#si',$str,$match,PREG_OFFSET_CAPTURE)){    //对中间不存在<div的字符串进行匹配，记录偏移量
        $start = $match[0][1];    //$match[0][1] 为匹配字符的起始
        $end = $match[0][1]+strlen($match[0][0]);    //匹配字符的起始（$match[0][1]）加上其长度（strlen($match[0][0])）
        $str = substr($str,0,$start) . substr($str,$end);    //原来$str为 substr($str,0,$start) . $match[0][0] . substr($str,$end);现在去掉中间部分。
        $results[] = $match[1][0];    //$match[1][0] 小括号匹配部分
    }

    echo '<pre>';
    print_r($results);        //匹配结果为逆序的
    krsort($results);        //倒序排序一下
    print_r($results);        //顺序结果

//End_php

JS:

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1、为document.getElementById('xxx')扩展函数
<input type="button" value="AddItem" id="AddItem"></input>
<div id="Items"></div>
<script type="text/javascript">
    Element.prototype.addItem = function(value,type,args){
        if(!type) type = 'div';
        var obj = document.createElement(type);
        obj.innerHTML = value;
        for(var key in args){
            obj.setAttribute(key,args[key]);
        }
        this.appendChild(obj);
    }
    document.getElementById('AddItem').onclick = function(){
        document.getElementById('Items').addItem('ABC','span',{'class':'item','id':'Item1'});
    }
</script>
同理，String.prototype.fname = function(){}可以为字符串扩展函数，Array.prototype.fname = function(){}可以为数组扩展函数。

2、新建js正则表达式模式
 var username = 'abc';
（1）、var p = /abc/gi;
（2）、var p = eval('/'+username+'/g');
（3）、var p = new RegExp(username,'g');

jQuery:

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1、jQuery(function($) {}) 与 (function($){})(jQuery)的区别

   # jQuery(function($) {}) 等价于 jQuery(document).ready(function($){}))（不适用于开发插件的代码）
   # (function($){})(jQuery)等价于var fun = function($){};fun(jQuery);（适用于开发插件的代码）

2、$("#myDiv").eq(0) 与 $("#myDiv").get(0)的区别
    # $("#myDiv").eq(0)返回的是jQuery对象，可以操作jQuery的方法、属性
    # $("#myDiv").get(0)返回的是Element对象，可以操作javascript方法、属性

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>防止嵌套事件传递</title>
<style>
.bbb{ display:none; padding-left:20px;}
</style>
</head>

<body>
<div class="aaa">1111
    <div class="bbb">
        <div class="aaa">222
            <div class="bbb">
                <div class="aaa">333
                    <div class="bbb">
                        <div class="aaa">444</div>
                        <div class="aaa">444</div>
                        <div class="aaa">444</div>
                        <div class="aaa">444</div>
                        <div class="aaa">444</div>
                    </div>
                </div>
                <div class="aaa">333</div>
                <div class="aaa">333</div>
                <div class="aaa">333</div>
                <div class="aaa">333</div>
            </div>
        </div>
        <div class="aaa">222</div>
        <div class="aaa">222</div>
        <div class="aaa">222</div>
        <div class="aaa">222</div>
    </div>
</div>
</body>
</html>
<script type="text/javascript" src="https://files.cnblogs.com/Zjmainstay/jquery-1.6.2.min.js"></script>
<script>
/*
//js版本
var oA=getByClass(document,'aaa');
for(var i=0; i<oA.length; i++){
    oA[i].onclick=function(ev){
        var ev=ev||window.event;
        var oDiv=this.getElementsByTagName('div')[0];
        if(oDiv){
            if(oDiv.style.display=='block'){
                oDiv.style.display='none';
            }else{
                oDiv.style.display='block';
            }
        }
        ev.cancelBubble = true;
    }
}
function getByClass(oParent,sClass){
    var aEle=oParent.getElementsByTagName('*');
    var arr=[];
    var re=new RegExp('\\b'+sClass+'\\b');
    for(var i=0; i<aEle.length; i++){
        if( re.test(aEle[i].className) ){
            arr.push(aEle[i]);
        }
    }
    return arr;
}
// */

// /*
//jQuery版本
$(document).ready(function(){
    $(".aaa").click(function(event){
        event = event || window.event;
        event.stopPropagation();
        if($(this).find('div').size()) {
            if($(this).find('div:first').css('display') == 'none'){
                $(this).contents().show();
            }else{
                $(this).contents().hide();
            }
        }
    });
});
// */
</script>

MySQL:

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1、mysql计算行总数
SELECT SQL_CALC_FOUND_ROWS ...
SELECT FOUND_ROWS()

-- Mysql 多表删除语句
-- 定义变量
SET @tables = null;
-- 拼接表名
SELECT GROUP_CONCAT(table_schema, '.', table_name) INTO @tables FROM information_schema.tables 
WHERE table_schema = 'test' AND table_name LIKE BINARY 'j_%';
-- 拼接DROP table 语句
SET @tables = CONCAT('DROP table  ', @tables);
-- 删表预处理语句
PREPARE stmt1 FROM @tables;
-- 执行删表预处理语句
EXECUTE stmt1;
-- 解除预处理语句
DEALLOCATE PREPARE stmt1;

-- 删除重复记录
DELETE FROM tb_test WHERE ID NOT IN(
    SELECT id from (
        SELECT MAX(ID) id FROM tb_test GROUP BY CID
    ) tmp -- delete 不能来自同名的select 表，所以此处需要添加一个tmp查询
)

-- 不使用tmp查询会导致 [Err] 1093 - You can't specify target table 'TB_TEST' for update in FROM clause 报错

CSS:

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1、Zen Coding（快捷键：Ctrl+E）
    E
    元素名称(div, p);
    E#id
    使用id的元素(div#content, p#intro, span#error);
    E.class
    使用类的元素(div.header, p.error.critial). 你也可以联合使用class和idID: div#content.column.width;
    E>N
    子代元素(div>p, div#footer>p>span);
    E+N
    兄弟元素(h1+p, div#header+div#content+div#footer);
    E*N
    元素倍增(ul#nav>li*5>a);
    E$*N
    条目编号 (ul#nav>li.item-$*5);
    
    难以区分层级的使用括号括起即可。

正则:

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1、汉字正则：
//js  /[\u4e00-\u9fa5]+/i 
//php /[\x7f-\xff]+/i

 Apache:

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RewriteEngine On

##http://test.com/htaccess/a.js        #重定向访问
##http://test.com/htaccess/a.jpg    #重定向访问
##http://test.com/htaccess/a.css    #直接访问
##http://test.com/htaccess/a.png    #直接访问
## 图片重定向
#RewriteCond %{REQUEST_FILENAME} \.(jpg|js)$
#RewriteCond %{REQUEST_URI} !^.*/local/.*$
#RewriteRule (.*) local/$1 [L]
## 等价
RewriteCond %{REQUEST_URI} !^.*/local/.*$
RewriteRule ^(.*)\.js$ local/$1.js [L,QSA]

## .htaccess 调控文件访问顺序
RewriteEngine On
<IfModule dir_module>
DirectoryIndex routeIndex.php index.html index.php
</IfModule>
## End