朋友问小弟我一个PHP的有关问题，自己不会，所以跑来问大家！

朋友问我一个PHP的问题，自己不会，所以跑来问大家！！
由于自己是搞JAVA的，但朋友问我一个PHP问题，内容如下：

PHP code

$testArr = array(    'php' => array(        'author' => 'allen',        'price' => 40,    ),    'java' => array(        'author' => 'james',        'price' => 55,    ),    'mysql' => array(        'author' => 'gates',        'price' => 30,    ),    'html' => array(        'author' => 'bill',        'price' => 21,    ));

PHP code

uasort($testArr, create_function('$a,$b', 'return $a["price"]>$b["price"];'));//价格升序，降序改成<
[解决办法]
PHP code
<?    $testArr = array(        'php' => array(            'author' => 'allen',            'price' => 40,        ),        'java' => array(            'author' => 'james',            'price' => 55,        ),        'mysql' => array(            'author' => 'gates',            'price' => 30,        ),        'html' => array(            'author' => 'bill',            'price' => 21,        )    );    function my_sort($a, $b){      return $a['price'] > $b['price'];    }    uasort($testArr, "my_sort");    print_r($testArr);?>
[解决办法]
PHP code
foreach ($testArr as $v) {    $k[] = $v['price'];}array_multisort($k, SORT_DESC,$testArr);print_r(array_slice($testArr,0,3));
[解决办法]
楼上几位共使用了两种类型的三种方法
对比如下
PHP code
$testArr = array(    'php' => array(        'author' => 'allen',        'price' => 40,    ),    'java' => array(        'author' => 'james',        'price' => 55,    ),    'mysql' => array(        'author' => 'gates',        'price' => 30,    ),    'html' => array(        'author' => 'bill',        'price' => 21,    ));/*** 应用回调函数 ***/function func1($ar) {  uasort($ar, create_function('$a,$b', 'return $a["price"]>$b["price"];'));//价格升序，降序改成<}/*** 不使用回调函数 ***/function func2($ar) {  foreach ($ar as $key => $row) {    $price[$key] = $row['price'];  }  array_multisort($price, SORT_ASC,$ar);}/*** 应用 php5.3 闭包 ***/function func3($ar) {  array_multisort(array_map(function($v){return $v['price'];},$ar),$ar);}check_speed(200, 'func2', $testArr);check_speed(200, 'func3', $testArr);check_speed(200, 'func1', $testArr);