JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://rawgit.com/bowerjs/knockout/master/knockout.js"></script>
<ul data-bind="foreach: names">
    <li data-bind="text: myFunction($data)"></li>
</ul>

JavaScript

window.myFunction = function(str){
	return str + '--';
}

function demoViewModel() {
	this.names = ['a', 'b', 'c'];
}

var mm = new demoViewModel();

ko.applyBindings(mm);