echo(),print(),print_r()的区别

(http://blog.csdn.net/u013372487/article/details/47858995#) copy

  ";  
print $a;  
echo "
";  
print_r($a);  
echo "
";  
var_dump($a);  


$asd="1234556";  
echo strlen($asd);  
for($i=0;$i".$asd[$i]."
";  
}  
//header("location:aaa.php");  
include 'aaa.php';  
?>