JSFiddle - React, Tailwind, and code Playground
HTML
<input class="etape btn-info others">
<input class="etape btn-inverse others">
<input class="etape btn-danger others">
<input class="no">
<input class="no">
<input class="no">
JavaScript
$("input[class^='btn'], input[class*=' btn']").each(function(){
alert($(this).attr('class'));
})