简介

This extension aims at helping people making PHP a stronger typed language and can be a good alternative to scalar type hinting. It provides different typehandling classes as such as integer, float, bool, enum and string

Warning

此扩展是实验性 的。此扩展的表象，包括其函数名称以及其他此扩展的相关文档都可能在未来的 PHP 发布版本中未通知就被修改。使用本扩展风险自担。

add a note

User Contributed Notes 3 notes

down

jlozares at gmail dot com ¶

2 years ago


abstract class ContainerType{
    protected $value;
    protected $length;
    protected $isRealContainer;
    abstract protected function get_length();
    abstract protected function is_real_container();
    abstract protected function init();
}

class JLNumber extends ContainerType{
    public $value;
    public $length;
    public $isRealContainer;

    public function __construct($val){
        $this->value     = $val;
        $this->length     = 0;
        $this->isRealContainer = FALSE;
        return $this->init();
    }
    protected function get_length(){
        $this->length = strlen(trim($this->value));
        return $this;
    }
    protected function is_real_container(){
        $this->isRealContainer = is_numeric($this->value);
        return $this->isRealContainer;
    }

    protected function init(){
        if($this->is_real_container()){
            $this->get_length();
        }else{
            $this->value="";
        }
        return $this;
    }

    public function __toString(){
        $real = ($this->isRealContainer)?"TRUE":"FALSE";
        $str = "<pre>";
        $str .= "Class Name : ".get_class()."<br>";
        $str .= "Type : Number<br>";
        $str .= "Value : ".$this->value."<br>";
        $str .= "Length : ".$this->length."<br>";
        $str .= "Is Real Number : ".$real."<br><br>";
        $str .= "</pre>";
        return $str;
    }
}

down

-4

tom ¶

9 years ago


For backwards compatibility issues:

We do know that auto-unboxing works for strings, thanks to the __toString() magic function. Auto-unboxing for other scalar types may be tricky but possible, by using the same function with another return type (which of cause has some limitations).



However auto-boxing is a real challenge.

If you can provide any details, I would appreciate that.



For auto-unboxing see this code-fragment:



<?php

class MyString {

  private $value = "";

  public function __construct($string) {

    if (!is_string($string)) {

      throw new InvalidArgumentException();

    }

    $this->value = $string;

  }

  public function __toString() {

    return $this->value;

  }

}

?>



For other scalar types, all that changes is the constructor function. Anything else remains unchanged. (While you are at it, you may want to add some type conversion functions for your personal convenience.)



HowTo:



<?php

function foo(MyString $string)

{

  print "$string"; // auto-unboxing in action

}



// prints "Hello World!"

foo(new MyString("Hello World!"));

?>

down

-6

Tom ¶

9 years ago


For your information, here is another work-around for this issue, that even works with PHP4 (in case you need to be compatible):



<?php

/**

 * @param string $foo

 */

function foo($foo)

{

  assert('is_string($foo); // Invalid argument type');

  // do some foo

}

?>



This single-line of code should fix it for most people. It will throw an error whenever the expression evaluates to false (if $foo is not a string).



Most errors concerning scalar types are found during development or unit-testing. PHPUnit is fine with these and reports failed assertions as failed tests, also presenting the included message.

Note that assertions need to be turned on for this to work. See the manual page on assertions for more details.

Note that you may deactivate the checks on the target machine, so this comes without any performance penalty. So don't hesitate to make extensive use of this PHP-feature.



Note though: DON'T RELY ON ASSERTIONS FOR CHECKING USER INPUT!



In that case you may want to try this code:

is_string($foo) || trigger_error('String expected', E_USER_ERROR);



Or: simply throw an exception (as usual).

add a note

官方地址：https://www.php.net/manual/en/intro.spl-types.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络数据库面试 JAVA NoSQL C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 ADORecordSet对象 adodb手册 opcache预加载 Composer的Packagist资源 array_multisort() 多字段排序 mysql面试题 PHP json解析（json_decode）页面工具 php中几种注释规范 PHP5 扩展SOAP 调用 webservice PHPMailer设置utf8 PHPMailer字符集CharSet PHP获取指定函数定义在哪个文件中及行号 php扩展开发纯php实现DES以及TripleDES加密算法 php 修改图片大小

略微加速

PHP官方手册 - 互联网笔记

简介

User Contributed Notes 3 notes