Can you guys write me a very basic javascript code?

Question

I need a js code that will set p' s visibility value (css) to visible when they click a button that has the class of "button"?

Answer 1

HTML :
<p>Hello</p>
<button onclick="show()" id=btn>Show</button>

CSS :
p {visibility: hidden}

JS :
function show() {
document.getElementsByTagName("p")[0].style.visibility = visible
}