How to change the text when click on it? [duplicate]

This question already has an answer here:

• jQuery $(this) keyword 5 answers

I want any text on the site to change to 'Ok!' when I click on it.

I guess such a code:

if($('*').text() != ''){
    $(this).click(function() {
        $(this).text() = 'Ok!';
    });
}