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: good swimming: very well running: 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：
football: good swimming: very well running: 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: good swimming: very well running: not good
