Detailed explanation of PHP hexadecimal conversion examples
This article mainly introduces PHP base conversion, and analyzes the implementation techniques of 2, 8, 16, 36, 64 base to 10 base conversion based on specific examples. It has certain reference value. Friends who need it can Refer to the example below
This article describes PHP base conversion. Share it with everyone for your reference, the details are as follows:
can be realized:
Convert 10 to 2, 8, 16, 36, 62 hexadecimal
2 , 8, 16, 36, 62 hexadecimal conversion to decimal
Please note that when converting 2, 8, 16 hexadecimal, the system's own function is used.
So, no matter how high-precision conversion value is, it may be greater than 2147483646.
In addition,
32 base low precision conversion, maximum value: 2147483646;
32 base high precision conversion, maximum value: 77309411327;
64 base high precision conversion , maximum value: 133143986175.
jinzhi.php file, comes with demo function.
<?php $mtime1 = explode(" ", microtime()); $startTime = $mtime1[0] + $mtime1[1]; ?> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> <title>进制转换/title> </head> <body> <form id="jzh" name="jinzhih" method="post" action=""> <input name="go" type="hidden" value="100"> <table width="482" border="1" cellpadding="0" cellspacing="0" bordercolor="#FFE8E8" bgcolor="#F4F8FB"> <tr> <td width="194"><select name="jinzhi0" id="jinzhi0"> <option value="2">2</option> <option value="8">8</option> <option value="10" selected="selected">10</option> <option value="16">16</option> <option value="36">36</option> <option value="62">62</option> </select> 进制</td> <td width="275"><input name="zhi" type="text" id="zhi" /></td> </tr> <tr> <td>进行<input name="lx" type="radio" value="0" checked="checked" /> 普通<input type="radio" name="lx" value="1" />高精</td><td> </td> </tr> <tr> <td>转换为 <select name="jinzhi1" id="jinzhi1"> <option value="2" selected="selected">2</option> <option value="8">8</option> <option value="10">10</option> <option value="16">16</option> <option value="36">36</option> <option value="62">62</option> </select>进制,</td><td>总长度为 <input name="changdu" type="text" id="changdu" value="10" size="4" maxlength="2" /> 字符。</td></tr><tr> <td><input type="submit" name="Submit" value="提交" /></td> <td><input type="reset" name="Submit2" value="重置" /></td> </tr></table> <p>注意:仅能进行10进制转换为2、8、16、36、62进制;或反转换。</p></form> <?php class jinzhi_class { //10进制转2、8、16、36、62进制 function jinzhih_0($shu,$jinzhi,$w) { $zifu = ""; while ($shu!=0){ $linshi = $shu%$jinzhi; switch ($jinzhi){ case 2: $zifu = decbin($shu); return $zifu; case 8: $zifu = decoct($shu); return $zifu; case 16: $zifu = dechex($shu); return $zifu; case 36: if ($linshi>=10) { $zifu.= chr(($linshi+55)); }else{ $zifu.= $linshi;} break; case 62: if (($linshi>=10) && ($linshi36)) {$zifu.= chr($linshi+55);break;} if (($linshi>=36) && ($linshi62)) {$zifu.= chr($linshi+61);break;} $zifu.= $linshi;break; default: $zifu.= $linshi; break; } $shu = intval($shu/$jinzhi); } for ($i=strlen($zifu);$i$w;$i++) $zifu.="0"; return strrev($zifu);} //2、8、16、36、62进制转10进制 function jinzhih_1($zifu,$jinzhi,$w) { $shu=0; for ($i=0;$i=strlen($zifu)-1;$i++) { $linshi = substr($zifu,$i,1); switch ($jinzhi){ case 2: $shu = bindec($zifu); $i=strlen($zifu)+1; break; case 8: $shu = octdec($zifu); $i=strlen($zifu)+1; break; case 16: $shu = hexdec($zifu); $i=strlen($zifu)+1; break; case 36: if (ord($linshi)=57) {$shu+=(ord($linshi)-48)*pow($jinzhi,strlen($zifu)-$i-1); }else{ $shu=$shu + (ord($linshi)-55)*pow($jinzhi,strlen($zifu)-$i-1);} break; case 62: if (ord($linshi)=57) {$shu+=$linshi*pow($jinzhi,strlen($zifu)-$i-1); }elseif ((ord($linshi)>=65) && (ord($linshi)=90)){ $shu+= (ord($linshi)-55)*pow($jinzhi,strlen($zifu)-$i-1); }else{ $shu+= (ord($linshi)-61)*pow($jinzhi,strlen($zifu)-$i-1);} break; } } return $shu; } //10进制高精度转换2、8、16、36、62进制 function jinzhih_G0($shu,$jinzhi,$w) { $zifu = ""; while ($shu!=0){ $linshi = bcmod($shu,$jinzhi); switch ($jinzhi){ case 2: $zifu = decbin($shu); return $zifu; case 8: $zifu = decoct($shu); return $zifu; case 16: $zifu = dechex($shu); return $zifu; case 36: if ($linshi>=10) { $zifu.= chr(($linshi+55)); }else{ $zifu.= $linshi;} break; case 62: if (($linshi>=10) && ($linshi36)) {$zifu.= chr($linshi+55);break;} if (($linshi>=36) && ($linshi62)) {$zifu.= chr($linshi+61);break;} $zifu.= $linshi;break; default: $zifu.= $linshi; break; } $shu = intval(bcp($shu,$jinzhi)); } for ($i=strlen($zifu);$i$w;$i++) $zifu.="0"; return strrev($zifu);} //2、8、16、36、62进制高精度转换10进制 function jinzhih_G1($zifu,$jinzhi,$w) { $shu= ""; for ($i=0;$i=strlen($zifu)-1;$i++) { $linshi = substr($zifu,$i,1); switch ($jinzhi){ case 2: $shu = bindec($zifu); $i=strlen($zifu)+1; break; case 8: $shu = octdec($zifu); $i=strlen($zifu)+1; break; case 16: $shu = hexdec($zifu); $i=strlen($zifu)+1; break; case 36: if (ord($linshi)=57) {$shu=bcadd($shu,bcmul((ord($linshi)-48),bcpow($jinzhi,strlen($zifu)-$i-1))); }else{ $shu=bcadd($shu,bcmul((ord($linshi)-55),bcpow($jinzhi,strlen($zifu)-$i-1)));} break; case 62: if (ord($linshi)=57) {$shu=bcadd($shu,bcmul($linshi,bcpow($jinzhi,strlen($zifu)-$i-1))); }elseif ((ord($linshi)>=65) && (ord($linshi)=90)){ $shu=bcadd($shu,bcmul((ord($linshi)-55),bcpow($jinzhi,strlen($zifu)-$i-1))); }else{ $shu=bcadd($shu,bcmul((ord($linshi)-61),bcpow($jinzhi,strlen($zifu)-$i-1))); } break; } } return $shu;} } if (isset($_GET["p"])) {if ($_GET["p"]==="1"){ echo ""; echo "提示: "; echo "32进制低精转换,最大值:2147483646 "; echo "32进制高精转换,最大值:77309411327 "; echo "64进制高精转换,最大值:133143986175 "; echo ""; echo "值为:"; $Fs = new jinzhi_class(); if ($_POST['lx']=="0" && $_POST['jinzhi0']=="10") {echo $Fs->jinzhih_0($_POST['zhi'],$_POST['jinzhi1'],$_POST['changdu'])." ";} if ($_POST['lx']=="1" && $_POST['jinzhi0']=="10") {echo $Fs->jinzhih_G0($_POST['zhi'],$_POST['jinzhi1'],$_POST['changdu']);} if ($_POST['lx']=="0" && $_POST['jinzhi0']>"10") {echo $Fs->jinzhih_1($_POST['zhi'],$_POST['jinzhi0'],$_POST['changdu']);} if ($_POST['lx']=="1" && $_POST['jinzhi0']>"10") {echo $Fs->jinzhih_G1($_POST['zhi'],$_POST['jinzhi0'],$_POST['changdu']);} } echo "";} $mtime1 = explode(" ", microtime()); $endTime = $mtime1[0] + $mtime1[1]; printf ("页面执行时间:%.6fs.",$endTime-$startTime); ?>
The above is the entire content of this article, I hope it will be helpful to everyone's study.
Related recommendations:
The difference between text files and binary files
Ajax sends and receives binary Method of byte stream data
PHP implements decimal ##, binary base, eight base and hexadecimal baseMethods for converting related functions
The above is the detailed content of Detailed explanation of PHP hexadecimal conversion examples. For more information, please follow other related articles on the PHP Chinese website!

Effective methods to prevent session fixed attacks include: 1. Regenerate the session ID after the user logs in; 2. Use a secure session ID generation algorithm; 3. Implement the session timeout mechanism; 4. Encrypt session data using HTTPS. These measures can ensure that the application is indestructible when facing session fixed attacks.

Implementing session-free authentication can be achieved by using JSONWebTokens (JWT), a token-based authentication system where all necessary information is stored in the token without server-side session storage. 1) Use JWT to generate and verify tokens, 2) Ensure that HTTPS is used to prevent tokens from being intercepted, 3) Securely store tokens on the client side, 4) Verify tokens on the server side to prevent tampering, 5) Implement token revocation mechanisms, such as using short-term access tokens and long-term refresh tokens.

The security risks of PHP sessions mainly include session hijacking, session fixation, session prediction and session poisoning. 1. Session hijacking can be prevented by using HTTPS and protecting cookies. 2. Session fixation can be avoided by regenerating the session ID before the user logs in. 3. Session prediction needs to ensure the randomness and unpredictability of session IDs. 4. Session poisoning can be prevented by verifying and filtering session data.

To destroy a PHP session, you need to start the session first, then clear the data and destroy the session file. 1. Use session_start() to start the session. 2. Use session_unset() to clear the session data. 3. Finally, use session_destroy() to destroy the session file to ensure data security and resource release.

How to change the default session saving path of PHP? It can be achieved through the following steps: use session_save_path('/var/www/sessions');session_start(); in PHP scripts to set the session saving path. Set session.save_path="/var/www/sessions" in the php.ini file to change the session saving path globally. Use Memcached or Redis to store session data, such as ini_set('session.save_handler','memcached'); ini_set(

TomodifydatainaPHPsession,startthesessionwithsession_start(),thenuse$_SESSIONtoset,modify,orremovevariables.1)Startthesession.2)Setormodifysessionvariablesusing$_SESSION.3)Removevariableswithunset().4)Clearallvariableswithsession_unset().5)Destroythe

Arrays can be stored in PHP sessions. 1. Start the session and use session_start(). 2. Create an array and store it in $_SESSION. 3. Retrieve the array through $_SESSION. 4. Optimize session data to improve performance.

PHP session garbage collection is triggered through a probability mechanism to clean up expired session data. 1) Set the trigger probability and session life cycle in the configuration file; 2) You can use cron tasks to optimize high-load applications; 3) You need to balance the garbage collection frequency and performance to avoid data loss.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

WebStorm Mac version
Useful JavaScript development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Zend Studio 13.0.1
Powerful PHP integrated development environment
