JSFiddle - React, Tailwind, and code Playground

HTML

<div id="a" class="input1 foo"></div>
<div id="b" class="foo input2"></div>
<div id="c" class="xinput3 foo"></div>

JavaScript

$.expr[':'].hasClassStartingWithInput = function(obj){
  return ((/\binput/).test(obj.className));
};

alert($('div:hasClassStartingWithInput').length);