如何替换除文本以外的所有内容[重复]

I'm looking to replace every thing except text between two string in php example: Watch Sidney's video

i want to replace "Watch 's video" with nothing and just keep "Sidney"

need to be in this format preg_replace("regex code", "replace with", input text)

</div>

You can do it using the following regex :

/Watch (\w*)'s video/

and you can replace with \1

Live demo here

Update

Sample code in php :

echo preg_replace('/Watch (\w*)\'s video/', "\\1", 'Watch Sidney\'s video');

Output

Sidney

You can make use of following explode() function for this:

$returnValue = explode(' ', 'Watch Sidney\'s video');

This will return an array as:

array (
  0 => 'Watch',
  1 => 'Sidney's',
  2 => 'video',
)

Now check the entries of array for string with 's and once you get it, trim 's off as :

$myString  str_replace("\'s","",$returnValue[some_index]);

This'll give you the text between the first space and the first apostrophe (assuming these criteria are constant):

<?php
$message = "Watch Sidney's video";
$start = strpos($message, " ");
$finish = strpos($message, "'");
echo substr($message, $start, $finish-$start);

// replace apostrophe (') or words without possessive contraction ('s) (Watch, video) with empty string
preg_replace("/(?:'|\s?\b\w+\b\s?)(?!'s)/", "", "Watch Sidney's video") // => Sidney

Try it here: https://regex101.com/r/sC7GyQ/1

If you want to extract video author's name - you may use extracting preg_match like this:

$matches = [];
preg_match('@Watch (\w+)\'s video@', $source, $matches);

echo $matches[1];