


Reading Chinese character dot matrix data using PHP programming_PHP tutorial
Background knowledge:
Simplified Chinese national standard font (issued in 1981, Mainland China). There are 7445 characters, including 6773 Chinese characters, including 3755 first-level Chinese characters and 3008 second-level Chinese characters. Using 2-byte (16-bit binary) encoding.
Location code: National standard GB2312 stipulates that all national standard Chinese characters and symbols form a 94×94 matrix. In this square matrix, each row is called a "area" and each column is called a "bit". Therefore, this square matrix actually forms a 94-area area (area numbers are 0 1 to 94 respectively), each There are 94 digits (digit numbers are 01 to 94) of Chinese character sets in the area. The area code and location number of a Chinese character are simply combined to form the "location code" of the Chinese character. In the area code of Chinese characters, the upper two digits are the area code and the lower two digits are the position number. It can be seen that there is a one-to-one correspondence between location codes and Chinese characters or symbols.
Internal code: The internal code of Chinese characters refers to the encoding of Chinese characters in computers. The in-machine code is slightly different from the location code. Why not directly use the area code as the internal code in the computer? This is because the area code and bit code of Chinese characters range from 1 to 94. If the area code is directly used as the internal code, it will conflict with the basic ASCII code. The internal code of Chinese characters is usually related to the computer system used. Currently, for most computer systems in China, the internal code of a Chinese character occupies two bytes, which are called high-order byte and low-order byte respectively, and the relationship between these two bytes and the area code is as follows: Internal code high-order = area Code + A0H (H represents hexadecimal) The low digit of the inner code = bit code + A0H. For example, the area code of the Chinese character "ah" is "1601", and the area code and bit code are expressed in hexadecimal respectively, which is "1001H" , then its internal code is "B0A1H". Among them, B0H is the high-order byte of the internal code, and A1H is the low-order byte of the internal code.
php(as the current mainstream development language)Code: Returns a string composed of 0 and 1.
<?php(as the current mainstream development language)
/**
* Read Chinese character dot matrix data
*
* @author legend <legendsky@hotmail.com>
* @link http://www.ugia.cn/?p=82
* @Copyright www.ugia.cn
*/
$str = "People's Republic of China";
$font_file_name = "simsun12.fon" ; // Bitmap font file name
$font_width = 12 ; // Single character width
$font_height = 12 ; // Single character height
$ start_offset = 0 ; // Offset
$fp = fopen ( $font_file_name , "rb" );
$offset_size = $font_width * $font_height / 8 ;
$string_size = $font_width * $font_height ;
$dot_string = "" ;
for ( $i = 0 ; $i < strlen ( $str ); $i ++)
{
if ( ord ( $str { $i }) > 160 )
{
// First find the location code, and then calculate its position in the two-dimensional table of location codes, and then get the position of this character in the file Offset
$offset = (( ord ( $str { $i }) - 0xa1 ) * 94 + ord ( $str { $i + 1 }) - 0xa1 ) * $offset_size ;
$i ++ ;
}
else
{
$offset = ( ord ( $str { $i }) + 156 - 1 ) * $offset_size ;
}
// Read its lattice data
fseek ( $fp , $start_offset + $offset , SEEK_SET );

APHPDependencyInjectionContainerisatoolthatmanagesclassdependencies,enhancingcodemodularity,testability,andmaintainability.Itactsasacentralhubforcreatingandinjectingdependencies,thusreducingtightcouplingandeasingunittesting.

Select DependencyInjection (DI) for large applications, ServiceLocator is suitable for small projects or prototypes. 1) DI improves the testability and modularity of the code through constructor injection. 2) ServiceLocator obtains services through center registration, which is convenient but may lead to an increase in code coupling.

PHPapplicationscanbeoptimizedforspeedandefficiencyby:1)enablingopcacheinphp.ini,2)usingpreparedstatementswithPDOfordatabasequeries,3)replacingloopswitharray_filterandarray_mapfordataprocessing,4)configuringNginxasareverseproxy,5)implementingcachingwi

PHPemailvalidationinvolvesthreesteps:1)Formatvalidationusingregularexpressionstochecktheemailformat;2)DNSvalidationtoensurethedomainhasavalidMXrecord;3)SMTPvalidation,themostthoroughmethod,whichchecksifthemailboxexistsbyconnectingtotheSMTPserver.Impl

TomakePHPapplicationsfaster,followthesesteps:1)UseOpcodeCachinglikeOPcachetostoreprecompiledscriptbytecode.2)MinimizeDatabaseQueriesbyusingquerycachingandefficientindexing.3)LeveragePHP7 Featuresforbettercodeefficiency.4)ImplementCachingStrategiessuc

ToimprovePHPapplicationspeed,followthesesteps:1)EnableopcodecachingwithAPCutoreducescriptexecutiontime.2)ImplementdatabasequerycachingusingPDOtominimizedatabasehits.3)UseHTTP/2tomultiplexrequestsandreduceconnectionoverhead.4)Limitsessionusagebyclosin

Dependency injection (DI) significantly improves the testability of PHP code by explicitly transitive dependencies. 1) DI decoupling classes and specific implementations make testing and maintenance more flexible. 2) Among the three types, the constructor injects explicit expression dependencies to keep the state consistent. 3) Use DI containers to manage complex dependencies to improve code quality and development efficiency.

DatabasequeryoptimizationinPHPinvolvesseveralstrategiestoenhanceperformance.1)Selectonlynecessarycolumnstoreducedatatransfer.2)Useindexingtospeedupdataretrieval.3)Implementquerycachingtostoreresultsoffrequentqueries.4)Utilizepreparedstatementsforeffi


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

SublimeText3 Linux new version
SublimeText3 Linux latest version

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.
