问计算文本中单词的出现情况

EN

$haystack = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ipsum lorem dolor Curabitur ac risus nunc. Dolor ipsum lorem.';
$needle = 'Lorem ipsum dolor';

$hayWords = str_word_count(
    strtolower($haystack), 
    1
);
$needleWords = str_word_count(
    strtolower($needle), 
    1
);
$needleWordsCount = count($needleWords);

$foundWords = array_intersect(
    $hayWords, 
    $needleWords
);

$count = array_reduce(
    array_keys($foundWords),
    function($counter, $item) use ($foundWords, $needleWordsCount) {
        for($i = $item; $i < $item + $needleWordsCount; ++$i) {
            if (!isset($foundWords[$i]))
                return $counter;
        }
        return ++$counter;
    },
    0
);

var_dump($count);

/(?:(?:(?:lorem|ipsum|dolor)\s?)+)/gi

<?php

$string = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ipsum lorem dolor Curabitur ac risus nunc. Dolor ipsum lorem.';

$lower_string = strtolower($string);

$text = array('lorem', 'ipsum', 'dolor');

$perms = AllPermutations($text);
$result = 0;
foreach ($perms as $piece) {
    $phrase = join(' ', $piece);
    $result += substr_count($lower_string, $phrase);
}

# From http://stackoverflow.com/a/12749950/1578604
function AllPermutations($InArray, $InProcessedArray = array())
{
    $ReturnArray = array();
    foreach($InArray as $Key=>$value)
    {
        $CopyArray = $InProcessedArray;
        $CopyArray[$Key] = $value;
        $TempArray = array_diff_key($InArray, $CopyArray);
        if (count($TempArray) == 0)
        {
            $ReturnArray[] = $CopyArray;
        }
        else
        {
            $ReturnArray = array_merge($ReturnArray, AllPermutations($TempArray, $CopyArray));
        }
    }
    return $ReturnArray;
}

echo $result;
?>

$text = 'This is a test';
echo strlen($text); // 14

echo substr_count($text, 'is'); // 2

// the string is reduced to 's is a test', so it prints 1
echo substr_count($text, 'is', 3);

// the text is reduced to 's i', so it prints 0
echo substr_count($text, 'is', 3, 3);

// generates a warning because 5+10 > 14
echo substr_count($text, 'is', 5, 10);


// prints only 1, because it doesn't count overlapped substrings
$text2 = 'gcdgcdgcd';
echo substr_count($text2, 'gcdgcd');