jquery select by data- value that is a variable

I'm having trouble applying answers from similar questions to my situation and I think it is because the value I'm looking for is a variable and not a constant string like most others. I have a variable `activeSlide` equal to the active slide: 1, 2, or 3. I want the button whose `data-dir = activeSlide` to show bold text but I can't seem to select the button based on the data- value. I can select an exact slide number with: ``` $('btns [data-dir=2]')... ``` But replacing 2 with `activeSlide` or `#{activeSlide}` isn't yielding any results. I'm about to re-write all my code with classes instead of the data- that is confusing me! Before I do that would someone mind showing me how I can select the button whose data-dir=activeSlide ? html: ``` <div class='btns'> <button data-dir='1'>1</button> <button data-dir='2'>2</button> <button data-dir='3'>3</button> </div> ```