when is the_title() set?

I am writing a plugin that needs to only run on one page of the blog. I don’t know if there’s a canonical way to do this, but I tried doing it by getting the name of the current page from the built-in function “the_title()”

Let’s say I have a WordPress page named “test” and the permalink for it is also “test” (so I would expect the_title() to return the string “test”)

I have a file in my plugins directory: plugins/my_plugin/my_plugin.php

And the contents of this file are:

<?php
/*
Plugin Name: my_plugin
*/

if (the_title()=="test") {
   ... do stuff...
}
?>

but this doesn’t work, and adding an “else” clause like:

else {
    $the_title=the_title()
    echo "THE TITLE IS '$the_title'";
}

reveals that the_title() is returning the empty string. Other functions like “the_permalink()” also return the empty string.

Why don’t these functions work? Or, what is a better way to make my plugin run on only one page?

Thank you.