Wordpress PHP How to Get a Function's Return Value Into an If() Statemente

I'm trying to create and if() statement that works in accordance to the kind of post (i.e., page or article) and, if page, the title of such page.

The type of post can be obtained from its class function post_class() and the title from its title function the_title().

So I know where I can get the info I need but, then, no matter what, I cannot turn this info into a string I can test. Wherever I put any of these two functions I get an output onto the page.

First, I tried:

if(strpos(post_class(), 'page')) {
    //DO SOMETHING
}

Didn't work. Just had the post_class() dumped onto the page.

Then, I tried calling the function as the value of a variable:

$this_class = post_class();

And had the same result.

I've since tried a couple of other dirtier ways of doing it but to no avail. It seems wherever these WP functions are placed, they will dump their values onto the page.

Perhaps somebody out there knows how I can successfully get the type of post and title and set them to if() statements in order to trigger whatever else.

Thanks!