用正则表达式提取两个单词之间的单词

I have a string:

8 nights you doodle poodle

I wish to retrieve every thing between nights and poodle, so in the above example, the output should be you doodle.

I'm using the below regex. Please can someone point out what I may be doing wrong?

if (preg_match("nights\s(.*)\spoodle", "8 nights you doodle poodle", $matches1)) {
    echo $matches1[0]."<br />"; 
}

You're close, but you're accessing the wrong index on $matches1. $matches1[0] will return the string that matched in preg_match();

Try $matches1[1];

Also, you need to enclose your regex in / characters;

if (preg_match("/nights\s(.*)\spoodle/", "8 nights you doodle poodle", $matches1)) {
    echo $matches1[1]."<br />"; 
}

Output

you doodle<br />

You probably want something like this

if (preg_match("/nights\s(.*)\spoodle/", "8 nights you doodle poodle", $matches1)) {
    echo $matches1[1]."<br />"; 
}

Check out rubular.com to test your regular expressions. Here is another relevant question: