PHP無法重新聲明類

Question

我發現以前的代碼（來自上一個問題）太慢了，無法完成我想要的操作，所以現在我有了一個快速運行的代碼。 我添加了一個簡單的代碼來計數。 至於不能重新聲明類，我已經閱讀了其他問題，這些問題涉及到引用諸如require_once（something.php）之類的.php文件。除此之外，我沒有任何其他文件。 我嘗試設置兩個文件，所以我確實有一個.php文件，但是隨后出現多個錯誤。 這是我的代碼。

<?php
error_reporting(E_ALL);
ini_set("display_errors", 1);
ini_set("log_errors", 0);

$numbers = 0;
$amout = 0;

while ($numbers < 50) {
    $numbers + 1;

// This till end of class is to get the divisor numbers
class Divisors {
  public $factor = array();

  public function __construct($num) {
    $this->num = $num;
  }

  // count number of divisors of a number
  public function countDivisors() {
    if ($this->num == 1) return 1;

    $this->_primefactors();

    $array_primes = array_count_values($this->factor);
    $divisors = 1;
    foreach($array_primes as $power) {
      $divisors *= ++$power;
    }
    return $divisors;
  }

  // prime factors decomposer
  private function _primefactors() {
    $this->factor = array();
    $run = true;
    while($run && @$this->factor[0] != $this->num) {
      $run = $this->_getFactors();
    }
  }

  // get all factors of the number
  private function _getFactors() {
    if($this->num == 1) {
      return ;
    }
    $root = ceil(sqrt($this->num)) + 1;
    $i = 2;
    while($i <= $root) {
      if($this->num % $i == 0) {
        $this->factor[] = $i;
        $this->num = $this->num / $i;
        return true;
      }
      $i++;
    }
    $this->factor[] = $this->num;
    return false;
  }
} // our class ends here

$example = new Divisors($numbers);
// Here it will check if the divisor has 5 divisors
if ($example->countDivisors() == 5) {
    // if true it will add 1 to the amount of numbers with 5 divisors
    $amount + 1;
}
}
// when the loop has checked 50 numbers it will print the amount
if ($numbers == 50){
    print "There are $amount numbers with 5 divisors";
}
?>

我該如何解決？ （第二是該類無效的代碼？）

Answer 1

您的類在while循環中聲明，並且每次迭代都會重新聲明。

您可能的意思是，每次迭代都為其創建一個新實例。

這是修改后的代碼

<?php
error_reporting(E_ALL);
ini_set("display_errors", 1);
ini_set("log_errors", 0);

// This till end of class is to get the divisor numbers
class Divisors
{
  public $factor = array();

  public function __construct($num) {
    $this->num = $num;
  }

  // count number of divisors of a number
  public function countDivisors() {
    if ($this->num == 1) return 1;

    $this->_primefactors();

    $array_primes = array_count_values($this->factor);
    $divisors = 1;
    foreach($array_primes as $power) {
      $divisors *= ++$power;
    }
    return $divisors;
  }

  // prime factors decomposer
  private function _primefactors() {
    $this->factor = array();
    $run = true;
    while($run && @$this->factor[0] != $this->num) {
      $run = $this->_getFactors();
    }
  }

  // get all factors of the number
  private function _getFactors() {
    if($this->num == 1) {
      return ;
    }
    $root = ceil(sqrt($this->num)) + 1;
    $i = 2;
    while($i <= $root) {
      if($this->num % $i == 0) {
        $this->factor[] = $i;
        $this->num = $this->num / $i;
        return true;
      }
      $i++;
    }
    $this->factor[] = $this->num;
    return false;
  }
} // our class ends here

$numbers = 0;
$amout = 0;

while ($numbers < 50)
{
    $numbers + 1;

    $example = new Divisors($numbers);
    // Here it will check if the divisor has 5 divisors
    if ($example->countDivisors() == 5) {
        // if true it will add 1 to the amount of numbers with 5 divisors
        $amount + 1;
    }
}
// when the loop has checked 50 numbers it will print the amount
if ($numbers == 50){
    print "There are $amount numbers with 5 divisors";
}
?>