如何使用PHP找到给定段落中的破折号？

I have Below Paragraph. I want to Find Number of Dashes araises in given paragraph??

1.I opened ______ door and found ______ old man wearing ______ hat standing on _____ doorstep.

Is Possible??

You should use substr_count

Just declare your text in a variable and count it

<?php
$text = "1.I opened ______ door and found ______ old man wearing ______ hat standing on _____ doorstep.";
echo substr_count($text,"_______");
?>

Note : It will count the number of _____ . [Dashes _____ is 5in count]

Here is the demo

Ok so the OP wants to count the number of words to be filled in represented by a series of underscores.

The number of underscores can also vary, I'm guessing to represent the length of the word.

So a more generic solution would be... Set the regex for the desired pattern

$search_string = '/[^_]?[_]+[^_]?/'; // Looking for one or more '_' sequences

A simpler version would be

$search_string = '/[_]{2,}/'; // Looking for at least 2 '_' sequences

Perform the blank word count where needed.

$word_count = preg_match_all($search_string,$text);
echo $word_count; // Just show the count for testing

The regex is pretty generic but should work for the above cases.

Additional: You are much better off creating a function to implement this.

function count_blank_words($text){
    $search_string = '/[_]{2,}/'; // Looking for at least 2 '_' sequences
    return preg_match_all($search_string,$text);
}

and call it using

echo count_blank_words($text);