PHP：将句子的单词组合成具有固定数量单词的较小组

Question

I have sentence like this:

I am in love with you

I want this to be in following combination for 3 words from left to right.

I am in
am in love
in love with
love with you

I tried the code below, but I think I'm complicating it...

$data = array_chunk(explode(" ", $sarr), 3);
$data = array_map(function($value) {
    return sprintf("<span>%s</span>", implode(" ", $value));
}, $data);
echo implode("
", $data);

Any ideas on how to do it fast and efficiently? This must work for 5000 words.

Answer 1

You could use Regular Expressions to work around this. You match one word then capture two other following words with a positive lookahead and stick them together within a foreach loop.

$words = [];
preg_match_all('~\b\w+(?=((?:\s+\w+){2}))~', $str, $matches);
foreach ($matches[0] as $key => $word) {
    // 1st iteration => $word = "I", $matches[1][0] = " am in"
    $words[] = $word . $matches[1][$key];
}

Outputs (print_r($words);):

Array
(
    [0] => I am in
    [1] => am in love
    [2] => in love with
    [3] => love with you
)

Output of echo implode(PHP_EOL, $words);:

I am in
am in love
in love with
love with you