Simple Underscore Template

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.5.2/underscore-min.js"></script>

JavaScript

function Repeter(pMessage) {
  var Template ='<%= message %><%= calc %>';
  return _.template(Template, {
    message: 'repetition',
    calc: for (i = pMessage; i < 5; i++) {
    text +=  "+ i +"
}
  });
}

var html = Repeter(8);
document.body.innerHTML = html;