PHP - 带空格的strpos（）

imap subject = "code. 115 is your id"

I tried using below one but didnt worked.

$headerInfo = imap_headerinfo($connection);
if (!strpos($headerInfo->subject, "code. $id")) {
    echo true 
}

$headerInfo = imap_headerinfo($connection);
if (!strpos($headerInfo->subject, "code.$id")) {
    echo true 
}

How can I fetch that?

You could extract the $id using a regular expression capture group.

<?php
$id = getId('imap subject = "code. 115 is your id"'); // is 115
$id = getId('imap subject = "code.115.00 is your id"'); // is 115

function getId($subject) {
    $r = [];
    if (preg_match("/code\. ?([0-9]+)(\.00)? is your id/", $subject, $r)) {
        return $r[1];
    }
    else {
        throw new Exception("Couldn't match subject");
    }
}

Now you only need to check if this $id is your id :)

$id = getId($headerInfo->subject);
if ($id == '119')

strpos will return 0, because code is at the start of the string. 0 evaluates to false when using a loose comparison such as !. What you need to do is make sure it doesn't have a strict evaluation to false:

if (strpos($headerInfo->subject, "code. $id") !== FALSE) {
    echo true;
}