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

<!--Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->$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,    ));

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PHP code

uasort($testArr, create_function('$a,$b', 'return $a["price"]>$b["price"];'));//价格升序，降序改成<font color="#e78608">------解决方案--------------------</font><br>

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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);?><br><font color="#e78608">------解决方案--------------------</font><br>

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PHP code

foreach ($testArr as $v) {    $k[] = $v['price'];}array_multisort($k, SORT_DESC,$testArr);print_r(array_slice($testArr,0,3));<br><font color="#e78608">------解决方案--------------------</font><br>楼上几位共使用了两种类型的三种方法<br>对比如下

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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 $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);<div class="clear">
                 
              
              
        
            </div>

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