Description
bool 
ctype_cntrl ( string text)
     Returns TRUE if every character in text has
     a special control function, FALSE otherwise. Control characters are
     e.g. line feed, tab, esc.
    
     
| 例子 1. A ctype_cntrl() example | 
<?php$strings = array('string1' => "\n\r\t", 'string2' => 'arf12');
 foreach ($strings as $name => $testcase) {
 if (ctype_cntrl($testcase)) {
 echo "The string '$name' consists of all control characters.\n";
 } else {
 echo "The string '$name' does not consist of all control characters.\n";
 }
 }
 ?>
 | 
 
       This example will output :
       | The string 'string1' consists of all control characters.
The string 'string2' does not consists of all control characters. | 
 |