php5.5新增 Finally模塊try { //好好干，出了問題不要怕，外面有人接應(yīng)} catch (HttpException $e) { //時刻準備著，處理上面拋出的HTTP問題} catch (Exception $e) { //時刻準備著，處理他們都處理不了的問題} finally { //打掃戰(zhàn)場，都收拾好了再走人}try 中 return 后 finally 會繼續(xù)執(zhí)行，如果 finally 中也有return，則最終返回值為 finally 中 return 的值。try 中 die 或 exit 后 finally 不會執(zhí)行。example01:

<?php/**finally塊是個很好的設(shè)計，其中的return語句能覆蓋其他塊中的return語句，并處理try catch拋出的異常無需try-catch嵌套來處理子try-catch拋出的異常這個跟java的一樣，c#是在finally塊中存在return語句會拋出compile time error（編譯時錯誤）*/function asdf(){    try {        throw new Exception('error');    }    catch(Exception $e) {        echo "An error occurred";        throw $e;    }    finally {                //This overrides the exception as if it were never thrown        return "/nException erased";    }}try {    echo asdf();}catch(Exception $e) {    echo "/nResult: " . $e->getMessage();}/* The output from above will look like this:     An error occurred     Exception erased Without the return statement in the finally block it would look like this:     An error occurred     Result: error*/

example02:

<?php/**有個相悖的行為在PHP 5.5.3's finally 和 return statements：在一個方法中，try塊單返回一個變量，finally塊修改這個變量，返回的是finally修改過的，但當try塊返回的變量參與運算（evaluated in-line），會忽略finally塊對這個變量的修改（不知道原因...）*/function returnVariable(){ $foo = 1; try{ return $foo; } finally { $foo++; } } function returnVariablePlusZero(){ $foo = 1; try{ return $foo+0; } finally { $foo++; } } $test1 = returnVariable(); // returns 2, not the correct value of 1. $test2 = returnVariablePlusZero(); // returns correct value of 1, but inconsistent with $test1.

example03:

<?php/**小例子 驗證變量check if the name contains only letters, and does not contain the Word name*/$name = "Name";try{        try        {                //PReg_match() 返回 pattern  的匹配次數(shù)。 它的值將是0次（不匹配）或1次，因為 preg_match() 在第一次匹配后 將會停止搜索。 preg_match_all() 不同于此，它會一直搜索 subject  直到到達結(jié)尾。 如果發(fā)生錯誤 preg_match() 返回 FALSE 。                if(preg_match('/[^a-z]/i', $name))                {                        throw new Exception("$name contains character other than a-z A-Z");                }                if(strpos(strtolower($name), 'name') !== false)                {                        throw new Exception("$name contains the word name");                }                echo "The Name is valid";        }        catch (exception $e)        {                throw new Exception("insert name again", 0, $e);        }}catch (exception $e){        if($e->getPrevious())        {                echo "The Previous Exception is: " . $e->getPrevious()->getMessage() . "<br/>";        }        echo "The Exception is: " . $e->getMessage() . "<br/>";}

example04

<?php/*When catching an exception inside a namespace it is important that you escape to the global space:如何逃離出命名空間*/ namespace SomeNamespace; class SomeClass {  function SomeFunction() {   try {    throw new Exception('Some Error Message');   } catch (/Exception $e) {    var_dump($e->getMessage());   }  } }//報錯：//Fatal error: Class 'SomeNamespace/Exception' not found in C:/xampp/htdocs/tonglei/index.php on line 8

example05

<?php//下面的寫法會報T_THROW Syntax Error.someFunction() OR throw new Exception();//這種寫法可以用下面這個正確的形式function throwException($message = null,$code = null) {    throw new Exception($message,$code);}someFunction() OR throwException();