Backend Development
PHP Tutorial
android studio uses php to reimplement the PHP script engine built-in functions
android studio uses php to reimplement the PHP script engine built-in functions
// I am really bored, and I had a sudden idea to re-implement some of the encapsulated functions in PHP using PHP.
// So I have the following code, which mainly implements some of the string processing functions in PHP, and at the same time There are no string processing functions in some PHP, but they are equally useful. These same functions can also be implemented in other languages
//, such as using C/VBScript/Perl, etc., then you can have A function library of your own. // The following functions may not necessarily run successfully, just for learning.
// /**
* String Functions Reconstruct
*
* Copyright (c) 2005 heiyeluren
* Author: heiyeluren
* $Id: StringFunctions.php,v 0.1 e 2005-5-29 23:21 heiyeluren Exp $
**/
// {{{ strlen()
/**
* Count string length
*
* @param string $str need count length string variable
* @return int return count result
* @version v0.1
* @create 2005-5-24
* @modified 2005-5-24
* @author heiyeluren
*/
function strlen1($str)
{
if ($str == '')
return 0;
$count = 0;
while (1)
{
if ($str[$count] != NULL)
{
$count++;
continue;
}
else
break;
}
return $count;
}
// }}}
//{{ substr()
/**
* Get sub string
*
* @param string $str need get sub string variable
* @param int $start start get sub string
* @param int $length need get string length
* @return string return sub string
* @version v0.2
* @create 2005-5-24
* @modified 2005-5-25
* @author heiyeluren
* /
function substr1($str, $start, $length=0)
{
if ($str == '')
return;
if ($start > strlen($str))
return;
if ( ($length != NULL) && ($start > 0) && ($length > strlen($str)-$start))
return;
if (($length != NULL) && ($start < 0) && ($length > strlen($str)+$start))
return;
if ($length == NULL)
$length = (strlen($str) - $start);
if ($start < 0)
{
for ($i=(strlen($str)+$start); $i<(strlen($str)+$start+$length); $i++)
{
$substr .= $ str[$i];
}
}
if ($length > 0)
{
for ($i=$start; $i<($start+$length); $i++)
{
$substr .= $str[$i];
}
}
if ($length < 0)
{
for ($i=$start; $i<(strlen($str)+$length); $i++)
{
$substr .= $str[$i];
}
}
return $substr;
}
// }}}
// {{{ strrev()
/**
* Reversal string order
*
* @param string $str need reversal string variable
* @return string reversal string
* @version v0.1
* @create 2005-5-24
* @modified 2005-5-24
* @author heiyeluren
*/
function strrev1($str)
{
if ($str == '')
return 0;
for ($i=(strlen($str)-1); $i>=0; $i--)
{
$rev_str .= $str[$i];
}
return $rev_str;
}
// }}}
// {{{ strcmp()
/**
* String comparison
*
* @param string $s1 first string
* @param string $s2 second string
* @return int return -1,str1 < str2; return 1, str1 > str2, str1 = str2,
* return 0, other, return false
* @version v0.1
* @create 2005-5-24
* @modified 2005-5-24
* @author heiyeluren
*/
function strcmp1($s1, $s2)
{
if (strlen($s1) < strlen($s2))
return -1;
if (strlen($s1) > strlen($s2))
return 1;
for ($i=0; $i
if ($s1[$i] == $s2[$i])
continue;
else
return false;
}
return 0;
}
// }}}
// {{{ strchr(), strstr(), strpos()
/**
* Find first occurrence of a string
*
* @param string $str parent string
* @param string $substr need match sub string
* @return int return find sub string at parent string first place,
* f not find, return false
* @version v0.4
* @create 2005-5-24
* @modified 2005-5-29
* @author heiyeluren
*/
function strchr1($str, $substr)
{
$m = strlen($str);
$n = strlen($substr);
if ($m < $n)
return false;
for ($i=0; $i<=($m-$n+1); $i++)
{
$sub = substr($str, $i, $n);
if (strcmp($sub, $substr) == 0)
return $i;
}
return false;
}
// }}}
// {{{ str_replace()
/**
* Replace all occurrences of the search string with the replacement string
*
* @param string $substr need replace sub string variable
* @param string $newsubstr new sub string
* @param string $str operate parent string
* @return string return replace after new parent string
* @version v0.2
* @create 2005-5-24
* @modified 2005-5-29
* @author heiyeluren
*/
function str_replace1($substr, $newsubstr, $str)
{
$m = strlen($str);
$n = strlen($substr);
$x = strlen($newsubstr);
if (strchr($str, $substr) == false)
return false;
for ($i=0; $i<=($m-$n+1); $i++)
{
$i = strchr($str, $substr);
$str = str_delete($str, $i, $n);
$str = str_insert($str, $i, $newstr);
}
return $str;
}
// }}}
/************ The following string processing functions are not available in PHP, so I wrote them myself for fun ***************/
// {{{ insert_str(), delete_str(), index_str()
/**
* Basic string operate
*
* @param string $str need get sub string variable
* @param int $start start get sub string
* @param int $length need get string length
* @return string return sub string
* @version v0.1
* @create 2005-5-24
* @modified 2005-5-24
* @author heiyeluren
*/
function str_insert($str, $i, $substr)
{
for($j=0; $j<$i; $j++)
{
$startstr .= $str[$j];
}
for ($j=$i; $j
$laststr .= $str[$j];
}
$str = ($startstr . $substr . $laststr);
return $str;
}
function str_delete($str, $i, $j)
{
for ($c=0; $c<$i; $c++)
{
$startstr .= $str[$c];
}
for ($c=($i+$j); $c
$laststr .= $str[$c];
}
$str = ($startstr . $laststr);
return $str;
}
// }}}
// {{{ strcpy()
/**
* Use designate sub string replace string
*
* @param string $str need get sub string variable
* @param int $start start get sub string
* @param int $length need get string length
* @return string return sub string
* @version v0.1
* @create 2005-5-27
* @modified 2005-5-27
* @author heiyeluren
*/
function strcpy($s1, $s2)
{
if (strlen($s1) == NULL)
return;
if (!isset($s2))
return;
for ($i=0; $i
$s2[] = $s1[$i];
}
return $s2;
}
// }}}
// {{{ strcat()
/**
* Use designate sub string replace string
*
* @param string $str need get sub string variable
* @param int $start start get sub string
* @param int $length need get string length
* @return string return sub string
* @version v0.1
* @create 2005-5-27
* @modified 2005-5-27
* @author heiyeluren
*/
function strcat($s1, $s2)
{
if (!isset($s1))
return;
if (!isset($s2))
return;
$newstr = $s1 . $s2;
return $newsstr;
}
// }}}
// {{{ php_encode(), php_decode()
/**
* Simple string encode/decode function
*
* @param string $str need code/encode string variable
* @return string code/encode after string
* @version v0.2
* @create 2005-3-11
* @modified 2005-5-24
* @author heiyeluren
*/
/* String encode function */
function php_encode($str)
{
if ($str=='' && strlen($str)>128)
return false;
for($i=0; $i
$c = ord($str[$i]);
if ($c>31 && $c<107)
$c += 20;
if ($c>106 && $c<127)
$c -= 75;
$word = chr($c);
$s .= $word;
}
return $s;
}
/* String decode function */
function php_decode($str)
{
if ($str=='' && strlen($str)>128)
return false;
for($i=0; $i
$c = ord($word);
if ($c>106 && $c<127)
$c = $c-20;
if ($c>31 && $c<107)
$c = $c+75;
$word = chr($c);
$s .= $word;
}
return $s;
}
// }}}
// {{{ php_encrypt(), php_decrypt()
/**
* Simple string encrypt/decrypt function
*
* @param string $str need crypt string variable
* @return string encrypt/decrypt after string
* @version v0.1
* @create 2005-5-27
* @modified 2005-5-29
* @author heiyeluren
*/
/* define crypt key */
$encrypt_key = 'abcdefghijklmnopqrstuvwxyz1234567890';
$decrypt_key = 'ngzqtcobmuhelkpdawxfyivrsj2468021359';
/* String encrypt function */
function php_encrypt($str)
{
global $encrypt_key, $decrypt_key;
if (strlen($str) == 0)
return false;
for ($i=0; $i
for ($j=0; $j
if ($str[$i] == $encrypt_key[$j])
{
$enstr .= $decrypt_key[$j];
break;
}
}
}
return $enstr;
}
/* String decrypt function */
function php_decrypt($str)
{
global $encrypt_key, $decrypt_key;
if (strlen($str) == 0)
return false;
for ($i=0; $i
for ($j=0; $j
if ($str[$i] == $decrypt_key[$j])
{
$enstr .= $encrypt_key[$j];
break;
}
}
}
return $enstr;
}
// }}}
如果代码不清晰的话，建议查看一下连接，是我在blogchina的博客：
http://heiyeluren.blogchina.com/1741318.html
以上就介绍了android studio 使用 使用php重新实现PHP脚本引擎内置函数，包括了android studio 使用方面的内容，希望对PHP教程有兴趣的朋友有所帮助。
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
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
Alipay PHP SDK transfer error: How to solve the problem of 'Cannot declare class SignData'?
Apr 01, 2025 am 07:21 AM
Alipay PHP...
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,
How does session hijacking work and how can you mitigate it in PHP?
Apr 06, 2025 am 12:02 AM
Session hijacking can be achieved through the following steps: 1. Obtain the session ID, 2. Use the session ID, 3. Keep the session active. The methods to prevent session hijacking in PHP include: 1. Use the session_regenerate_id() function to regenerate the session ID, 2. Store session data through the database, 3. Ensure that all session data is transmitted through HTTPS.
Describe the SOLID principles and how they apply to PHP development.
Apr 03, 2025 am 12:04 AM
The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.
How to debug CLI mode in PHPStorm?
Apr 01, 2025 pm 02:57 PM
How to debug CLI mode in PHPStorm? When developing with PHPStorm, sometimes we need to debug PHP in command line interface (CLI) mode...
Framework Security Features: Protecting against vulnerabilities.
Mar 28, 2025 pm 05:11 PM
Article discusses essential security features in frameworks to protect against vulnerabilities, including input validation, authentication, and regular updates.
How to automatically set permissions of unixsocket after system restart?
Mar 31, 2025 pm 11:54 PM
How to automatically set the permissions of unixsocket after the system restarts. Every time the system restarts, we need to execute the following command to modify the permissions of unixsocket: sudo...
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
