Home >Backend Development >PHP Tutorial >Detailed explanation of PHP standard specifications
Detailed explanation of PHP standard specifications
- 小云云Original
- 2018-03-19 14:14:423386browse
This article mainly shares with you the detailed explanation of PHP standard specifications, hoping to help everyone.
psr0: Automatic loading standard
has been replaced by psr4, you can learn about
1. Mandatory: Fully qualified namespace and class format: \
2. Mandatory: Each namespace must have a top-level namespace (Vendor Name).
3. Each namespace can contain any number of sub-namespaces.
4. When the file system loads the source file, the separator between namespaces will be converted to DIRECTORY_SEPARATOR.
5. Underscores _ in the class name
6. Fully qualified namespaces and classes will have the .php suffix added when loading source files from the file system.
7. Letter cases in a fully qualified namespace can be any combination.
Example
\Doctrine\Common\IsolatedClassLoader => /path/to/project/lib/vendor/Doctrine/Common/IsolatedClassLoader.php \Symfony\Core\Request => /path/to/project/lib/vendor/Symfony/Core/Request.php \Zend\Acl => /path/to/project/lib/vendor/Zend/Acl.php \Zend\Mail\Message => /path/to/project/lib/vendor/Zend/Mail/Message.php \namespace\package\Class_Name => /path/to/project/lib/vendor/namespace/package/Class/Name.php \namespace\package_name\Class_Name => /path/to/project/lib/vendor/namespace/package_name/Class/Name.php
psr1: Basic programming specifications
Mandatory: The php tag must be or = ?>2. Mandatory: The file must be encoded in UTF-8 without BOM 3. The code in the php file can only be declarations such as defining classes, functions, constants, etc., or it can only be some side operations 4. Namespaces and classes must meet psr0 or psr45. Class The name must be StudlyCaps [CamelCase naming starting with a capital] Specification 6. All letters of constants in the class must be capitalized and separated by underscores 7. Method names must be camelCase naming specifications.
Explanation
副操作包含却不仅限于：生成输出、直接的 require 或 include、连接外部服务、
修改 ini 配置、抛出错误或异常、修改全局或静态变量、读或写文件等。<?php// side effect: change ini settingsini_set('error_reporting', E_ALL);// side effect: loads a fileinclude "file.php";// side effect: generates outputecho "<html>\n";// declarationfunction foo(){
// function body}<?php// declarationfunction foo(){
// function body}// conditional declaration is not a side effectif (! function_exists('bar')) { function bar()
{
// function body
}
}psr2 programming style specification
is an extension of psr1
1. Must follow psr12. Indentation must use 4 spaces Character 3. The number of characters per line should be softly kept within 80. In theory, it must not be more than 120, but there must be no hard limit. 4. A blank line must be inserted after each namespace declaration and use declaration block. All uses must be declared after namespace. 5. The opening braces of methods and classes must be written on a new line after their declaration. 6. abstract and final must be before the modifiers private, protected and public, and static must be declared after the access modifier. 7. There must be a space after the keyword of the control structure, but it must not be when calling a method or function. 8. The opening brace of a control structure must be written on the same line as the declaration. 9. There must be no spaces after the opening left bracket and before the closing right bracket of the control structure. 10. All PHP files must use Unix LF as the line terminator.
11. All PHP files must end with a blank line. 12. There must be no extra spaces after a non-blank line. 13. There must be no more than one statement per line. 14. All PHP keywords must be in lowercase.
Instance
<?phpnamespace Vendor\Package;use FooInterface;use BarClass as Bar;use OtherVendor\OtherPackage\BazClass;class Foo extends Bar implements FooInterface{
public function sampleMethod($a, $b = null)
{
if ($a === $b) {
bar();
} elseif ($a > $b) { $foo->bar($arg1);
} else {
BazClass::bar($arg2, $arg3);
}
} final public static function bar()
{
// method body
}
}psr4 automatic loading
\
Note: no longer after psr4 It's called a fully qualified namespace, but a fully qualified class name. 1. A fully qualified class name must have a top-level namespace, called a "vendor namespace" 2. A fully qualified class name can have one or more sub-namespaces 3. A complete class name must have a final class name; 4 . Underscores have no special meaning. 5. The complete class name can be composed of any uppercase and lowercase letters; 6. All class names must be case-sensitive. 7. In the complete class name, remove the first namespace separator, and the preceding one or more consecutive namespaces and sub-namespaces are used as the "namespace prefix", which must correspond to at least one "file base directory"; 8. The subnamespace immediately following the namespace prefix must match the corresponding "file base directory", and the namespace delimiter will be used as the directory delimiter. 9. The class name at the end must have the same name as the corresponding file with the .php suffix. 10. The implementation of the autoloader must not throw exceptions, must not trigger any level of error messages, and should not have a return value.
Instance
| Namespace prefix | File base directory | File path | |
|---|---|---|---|
| Acme\Log\Writer | ./acme -log-writer/lib/ | ./acme-log-writer/lib/File_Writer.php | ##\Aura\Web\Response\Status |
| /path/to/aura-web/src/ | /path/to/aura-web/src/Response/Status.php | \Symfony\Core\Request | |
| ./vendor/Symfony/Core/ | ./vendor/Symfony/Core/Request .php | ##\Zend\Acl | |
| /usr/includes/Zend/ | /usr/includes/Zend /Acl.php | Related recommendations: |
php standard generation verification code program
The above is the detailed content of Detailed explanation of PHP standard specifications. For more information, please follow other related articles on the PHP Chinese website!