TEST_2.php

<?php

class Debug
{  
    public function getTest($x)
    {
        if ( !is_numeric($x) ) {
            throw new Exception('This not number');
        }
            return $x;
    }

}

class YuException extends Exception
{  
    public function errorMessage()
    {
        $errorMsg = 'Message: '.$this->getMessage();
        return $errorMsg;
    }
}

class DebugTwo
{  
    public function getTest($x)
    {
        if ( !is_numeric($x) ) {
            throw new YuException('This not number');
        }
            return $x;
    }  
}

$Debug = new Debug();
try {
    echo $Debug->getTest('1') . "\r\n";
    echo $Debug->getTest('A') . "\r\n";
    echo $Debug->getTest(0) . "\r\n";
} catch (Exception $e) {
    echo $e->getMessage()."\r\n";
}

$DebugTwo = new DebugTwo();
try {
    echo $DebugTwo->getTest('1') . "\r\n";
    echo $DebugTwo->getTest('A') . "\r\n";
    echo $DebugTwo->getTest(0) . "\r\n";
} catch (YuException $e) {
    echo $e->errorMessage()."\r\n";
}

$Debug = new Debug();
$DebugTwo = new DebugTwo();
try {
    echo $Debug->getTest('1') . "\r\n";
    echo $Debug->getTest('A') . "\r\n";
    echo $Debug->getTest(0) . "\r\n";
    echo $DebugTwo->getTest('1') . "\r\n";
    echo $DebugTwo->getTest('A') . "\r\n";
    echo $DebugTwo->getTest(0) . "\r\n";
} catch (YuException $e) {
    echo $e->getMessage()."\r\n";
} catch (Exception $e) {
    echo $e->getMessage()."\r\n";
} finally {
    echo "finish";
}