PHP100-6 编写一个函数解析多重嵌套数组的所有元素

$arr = array(array(1,2,array(3,4,5,array(6,7))),array(8,9),10,11);

function show_array($a){
<span style="color:#ff0000;">foreach</span> ($a as $key => $value) {
if(<span style="color:#ff0000;">is_array</span>($value)){
show_array($value);
}else{
echo $value."<br/>";
}
}
}

show_array($arr);