前天看了篇文章，是关于C#的异常处理的。文中提出C#中的异常处理会对程序的执行效率产生很大影响，对于相同的一个算法，使用异常处理和使用Return返回错误的程序的时间差可以达到6s : 1s。
<?phpfunction getmicrotime(){ list($usec, $sec) = explode(" ",microtime()); return ((float)$usec + (float)$sec); }$time_start = getmicrotime();class A { public function __construct() { $this->display(); } public function display() { throw new exception("Class A display() called.<br />"); }}class B extends A{ public function __construct() { $this->display(); } public function display() { try { parent::display(); } catch (exception $e) { throw new exception($e->getMessage()."Class B display() called.<br />"); } }}class C extends B{ public function __construct() { $this->display(); } public function display() { try { parent::display(); } catch (exception $e) { throw new exception($e->getMessage()."Class C display() called.<br />"); } }}class D extends C{ public function __construct() { $this->display(); } public function display() { try { parent::display(); } catch (exception $e) { throw new exception($e->getMessage()."Class D display() called.<br />"); } }}try { $ss = new d;} catch(exception $e){ echo $e->getMessage();}$time_end = getmicrotime();$time = $time_end - $time_start;echo "Did nothing in $time seconds";?>
<?phpfunction getmicrotime(){ list($usec, $sec) = explode(" ",microtime()); return ((float)$usec + (float)$sec); }$time_start = getmicrotime();class A { public function __construct() { $this->display(); } public function display() { echo "Class A display() called.<br />"; return false; }}class B extends A{ public function __construct() { $this->display(); } public function display() { if(!parent::display()) { echo "Class B display() called.<br />"; return false; } }}class C extends B{ public function __construct() { $this->display(); } public function display() { if(!parent::display()) { echo "Class C display() called.<br />"; return false; } }}class D extends C{ public function __construct() { $this->display(); } public function display() { if(!parent::display()) { echo "Class D display() called.<br />"; return false; } }} $ss = new d;$time_end = getmicrotime();$time = $time_end - $time_start;echo "Did nothing in $time seconds";?>
测试结果如下：
| exception处理 | return处理 | |
| 第一次 | 0.00075888633728s | 0.000170946121216s |
| 第二次 | 0.000414133071899s | 0.0001380443573s |
| 第三次 | 0.000410079956055s | 0.000159978866577s |
| 第四次 | 0.000416040420532s | 0.000160932540894s |
| 第五次 | 0.00037693977356s | 0.000144958496094s |
| 第六次 | 0.000380039215088s | 0.000140905380249s |
| 第七次 | 0.000383853912354s | 0.000147819519043s |
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