Hiding all elements with a given tag except one

Over 10 years ago, I made my first show/hide toggler and was very proud of it… and tonight I had to remember how to do these basics.

My script searches for section elements and hides all but the specified one — this will eventually be used as a way of handling my paginated quiz (each section being a “page”).

function hideAllButOne(displayDiv){
	var sections = document.getElementsByTagName('section');   
	
	for (var i = 0; i < sections.length; i++) {   
		var section_id = sections[i].getAttribute('id');
		
		if (section_id == displayDiv){
			sections[i].style.display = 'block';
		}
		
		else{
			sections[i].style.display = 'none';
		}
    }  
}  

I have a lot left to do, but this is a start.