设置两个迭代器并打印它们之间的所有内容。所以像这样：
<?$str = "How are you";$words = explode(" ",$str);$num_words = count($words);for ($i = 0; $i < $num_words; $i++) { for ($j = $i; $j < $num_words; $j++) { for ($k = $i; $k <= $j; $k++) { print $words[$k] . " "; } print "n"; }}?>输出量
How How are How are you are are you you
