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Introduction to PHP coding development specifications (with examples)

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2019-04-01 10:29:102632browse

This article brings you an introduction to PHP coding development specifications (with examples). It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

In the past few days, I have been reading a set of Java development specifications "Alibaba Java Development Manual" released by Alibaba Technology. It contains Alibaba's internal Java development specifications and standards, and it is very well written. This set of Java unified specifications will help improve the standardization level of industry coding, help industry personnel improve development quality and efficiency, and greatly reduce code maintenance costs.

After reading this, I searched for some PHP development specifications and standards, and learned that the PSR specification is a set of development standards commonly used in the PHP industry. I lament that I have learned so little and discovered the standard norms so late.

In fact, for novices or developers with several years of experience, we must master these specifications. In many cases, if we do these specifications well, in collaborative development, we can improve the quality and efficiency of our development.

What is PSR?

PSR is the abbreviation of PHP Standard Recommendations. The PHP specification developed by the PHP FIG organization is the practice standard for PHP development.

PHP FIG has currently voted to adopt 6 sets of standards and has been supported and recognized by most PHP frameworks.

Among them, the ones that have passed are:

  • PSR-1 basic coding specification
  • PSR-2 coding style specification
  • PSR-3 log interface specification
  • PSR-4 automatic loading specification
  • PSR-6 cache interface specification
  • PSR-7 HTTP message interface specification

*Note: PSR-0 has been deprecated and PSR-5 is still being drafted and will be added later

Here we first introduce the PSR-1 basic coding specifications

1. Overview

PHP code files must end with f9c32f061868e299801732108fc0e287 long tag Or e001818591141260ad444db4de1b1edb short output tag;

must not use other custom tags.

2.2. Character encoding

PHP code must and can only use UTF-8 encoding without BOM. (This is very important)

2.3. Side Effects

A PHP file should only define new declarations, such as classes, functions or constants, etc. Operations that produce side effects, or just write logical operations that produce side effects, but not both at the same time.

The term "side effects" means logical operations performed only by including files without directly declaring classes, functions, constants, etc.

"Side effects" include but are not limited to:

    Generate output
    Direct require or include
    Connect to external services
    Modify ini configuration
    Throw an error or exception
    Modify global or static variables
    Read or write files, etc.
The following is a counter-example, a file containing "function declaration" and "side effects" Code:

<?php
// 「副作用」:修改 ini 配置
ini_set(&#39;error_reporting&#39;, E_ALL);
// 「副作用」:引入文件
include "file.php";
// 「副作用」:生成输出
echo "<html>\n";
// 声明函数
function foo()
{
   // 函数主体部分
}

The following is an example, a code that only contains declarations and does not produce "side effects":


<?php
// 声明函数
function foo()
{
   // 函数主体部分
}
// 条件声明 **不** 属于「副作用」
if (! function_exists(&#39;bar&#39;)) {
   function bar()
   {
       // 函数主体部分
   }
}

3. Namespaces and classes

The naming of namespaces and classes must follow [PSR-4]().

According to the specification, each class is an independent file, and the namespace has at least one level: the top-level organization name (vendor name).

The naming of classes must follow the camel case naming convention of StudlyCaps starting with an uppercase letter.

Code for PHP 5.3 and later versions must use formal namespaces.

For example:

<?php
// PHP 5.3及以后版本的写法
namespace Vendor\Model;
class Foo
{
}

5.2.x 及之前的版本 应该 使用伪命名空间的写法,约定俗成使用顶级的组织名称(vendor name)如 Vendor_ 为类前缀。

<?php
// 5.2.x及之前版本的写法
class Vendor_Model_Foo
{
}

4. 类的常量、属性和方法

此处的「类」指代所有的类、接口以及可复用代码块(traits)。

4.1. 常量

类的常量中所有字母都 必须 大写,词间以下划线分隔。

参照以下代码:

<?php
namespace Vendor\Model;
class Foo
{
   const VERSION = &#39;1.0&#39;;
   const DATE_APPROVED = &#39;2012-06-01&#39;;
}

4.2. 属性

类的属性命名 可以 遵循:

  • 大写开头的驼峰式 ($StudlyCaps)
  • 小写开头的驼峰式 ($camelCase)
  • 下划线分隔式 ($under_score)

本规范不做强制要求,但无论遵循哪种命名方式,都 应该 在一定的范围内保持一致。这个范围可以是整个团队、整个包、整个类或整个方法。

4.3. 方法

方法名称 必须 符合 camelCase() 式的小写开头驼峰命名规范。

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