在PHP中数组分为两类： 数字索引数组和关联数组。其中数字索引数组和C语言中的数组一样，下标是为0，1，2…而关联数组下标可能是任意类型，与其它语言中的hash，map等结构相似。
下面介绍PHP中遍历关联数组的三种方法：
<?php$sports = array( 'football' => 'good', 'swimming' => 'very well', 'running' => 'not good' ); foreach ($sports as $key => $value) { echo $key.": ".$value."<br />";}?>
程序运行结果：
football: goodswimming: very wellrunning: not good
<?php$sports = array( 'football' => 'good', 'swimming' => 'very well', 'running' => 'not good' ); while ($elem = each($sports)) { echo $elem['key'].": ".$elem['value']."<br />";}?>
程序运行结果：程序运行结果：
football: goodswimming: very wellrunning: not good
<?php$sports = array( 'football' => 'good', 'swimming' => 'very well', 'running' => 'not good' ); while (list($key, $value) = each($sports)) { echo $key.": ".$value."<br />";}?>
程序运行结果：
football: goodswimming: very wellrunning: not good
