Class[OOP] 擴展了 PHP 中的問題

Question

我在 PHP 中有 3（三個）class

主要 Class 是檢測。php

檢測.php

<?php
include "Helper.php";
include "Unicode.php";
class Detection {

    private $helper;
    private $unicode;

    public function __construct() {
        mb_internal_encoding('UTF-8');
        $this->helper = new Helper();
        $this->unicode = new Unicode();
    }
    public function detect($text) {
        $arrayOfChar = $this->helper->split_char($text);
        $words = $this->helper->split_word($text);
        ................
        return $xxx;
    }
    ..............
}
$i = new Detection();
?>

助手.php

<?php
class Helper {

    public function __construct() {
    }
    public function split_word($text) {
        $array =  mb_split("\s", preg_replace( "/[^\p{L}|\p{Zs}]/u", " ", $text ));
        return $this->clean_array($array);
    }
    public function clean_array($array) {
        $array = array_filter($array);
        foreach($array as &$value) {
            $newArray[] = $value;
        } unset($value);
        return $newArray;
    }
    public function split_char($text) {
        return preg_split('/(?<!^)(?!$)/u', mb_strtolower(preg_replace( "/[^\p{L}]/u", "", $text )));
    }
    public function array_by_key($array, $key) {
        foreach($array as &$value) {
            $new_array[] = $value[$key];
        } unset($value);
        return $new_array;
    }
}
?>

Unicode.php

<?php
include "DatabaseConnection.php";
//include "Helper.php"; WHEN '//' double slash is removed, i got code is not working
class Unicode {

    private $connection;
    private $helper;
    public function __construct() {
        $this->connection = new DatabaseConnection();
        //$this->helper = new Helper(); WHEN '//' double slash is removed, i got code is not working
    }
.................
}
?>

在 Unicode.php 中，您可以看到有兩行我用雙斜杠“//”注釋。 當我刪除並運行代碼時，我在瀏覽器中出現白屏，這意味着發生了錯誤。 但是當我評論它時//包括“Helper.php”； 和 //$this->helper = new Helper(); 代碼工作正常。

Is there in OOP restriction to extend Helper.php in Unicode.php and Detection.php, that Detection.php extend Unicode.php

Answer 1

在第一次查看時，您似乎在重新聲明 class 'Helper' 時遇到錯誤。

在上面的示例中，您不需要在“Unicode.php”中包含“Helper.php”，因為您已經在“Detection.php”中包含了它。 如果您需要確保它被包含，您可以使用include_once() ，並且 PHP 將確保僅在第一次調用時包含該文件。