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PHP課程 / 析構(gòu)函數(shù)

析構(gòu)函數(shù)

PHP - __destruct 函數(shù)

當(dāng)對(duì)象被銷毀或腳本停止或退出時(shí),會(huì)調(diào)用析構(gòu)函數(shù)。

如果您創(chuàng)建一個(gè) __destruct() 函數(shù),PHP 將在腳本結(jié)束時(shí)自動(dòng)調(diào)用此函數(shù)。

請(qǐng)注意,析構(gòu)函數(shù)以兩個(gè)下劃線(__)開(kāi)頭!

下面的例子有一個(gè) __construct() 函數(shù),當(dāng)您從類中創(chuàng)建一個(gè)對(duì)象時(shí)會(huì)自動(dòng)調(diào)用它,以及一個(gè) __destruct() 函數(shù),它會(huì)在腳本結(jié)束時(shí)自動(dòng)調(diào)用:

實(shí)例

<?php
class Fruit {
  public $name;
  public $color;

  function __construct($name) {
    $this->name = $name;
  }
  function __destruct() {
    echo "The fruit is {$this->name}.";
  }
}

$apple = new Fruit("Apple");
?>
運(yùn)行實(shí)例 ?

點(diǎn)擊 "運(yùn)行實(shí)例" 按鈕查看在線實(shí)例

另一個(gè)例子:

實(shí)例

<?php
class Fruit {
  public $name;
  public $color;

  function __construct($name, $color) {
    $this->name = $name;
    $this->color = $color;
  }
  function __destruct() {
    echo "The fruit is {$this->name} and the color is {$this->color}.";
  }
}

$apple = new Fruit("Apple", "red");
?>
運(yùn)行實(shí)例 ?

點(diǎn)擊 "運(yùn)行實(shí)例" 按鈕查看在線實(shí)例

提示:由于構(gòu)造函數(shù)和析構(gòu)函數(shù)有助于減少代碼量,因此它們非常有用!