JSFiddle - React, Tailwind, and code Playground
by chovy
HTML
<div>
<p>
<input id="in" type="text" placeholder="Enter number">
</p>
<p>
<span id="out"></span>
</p>
</div>
JavaScript
var in = document.getElementById('in');
var out = document.getElementById('out');
in.onEnter = function(e){
out.innerHTML = this.value;
};
function insertDashes(str){
return str.replace(/([13579])(?=[13579])/, '$1-');
}