php中debug_backtrace、debug_print_backtrace和匿名函数用

one(); 
function one() {    two();     } 
function two() {    three();  } 
function three() {    print_r( debug_backtrace() );   } 
/输出 
Array( 
     [0] => Array        ( 
            [file] => D:apmservhtdocstestdebugindex.php 
            [line] => 10 
            [function] => three 
            [args] => Array                (                ) 
      ), 
      [1] => Array        ( 
           [file] => D:apmservhtdocstestdebugindex.php 
           [line] => 6 
           [function] => two 
           [args] => Array                (                ) 
      ), 
      [2] => Array        ( 
           [file] => D:apmservhtdocstestdebugindex.php 
           [line] => 3 
           [function] => one 
           [args] => Array                (                ) 
      ) 
)/

<?php 
echo preg_replace_callback('~-([a-z])~', function ($match) { 
    return strtoupper($match[1]); 
    }, 'hello-world'
); 
// 输出 helloWorld 
?>

function test(){ 
    $num = 2; 
    $array = array(1,2,3,4,5,6,7,8); 
    print_r(array_filter($array, function($param)  use ($num){ 
    return $param % intval($num) ==0; }) 
);}
test();