$words=array("l"=>"lemon","o"=>"orange","b"=>"banana","a"=>"apple");
//定义一个回调函数,输出数组元素
function words_print($value,$key,$prefix){
echo "$prefix:$key=>$value
n";
}
//定义一个回调函数直接改变元素的值
function words_alter(&$value,$key){
$value=ucfirst($value);
$key=strtoupper(key);
}
//输出元素的值
array_walk($words,'words_print','words');
//改变元素的值
array_walk($words,'words_alter');
echo "
";";
print_r($words);
echo "
运行效果如下:



