ES6 also introduces the concept of a module, which works similar to other languages. Defining an ES6 module is quite easy: each file is assumed to define a module and we specify its exported values using the export keyword.
Loading ES6 modules is a little trickier. In an ES6-compliant browser you use the System keyword to load modules asynchronously. To make our code work with current browsers, however, we will use the SystemJS library as a polyfill:
<script src="/node_module/systemjs/dist/system.js"></script>
<script>
var promise = System.import('app')
.then(function() {
console.log('Loaded!');
})
.then(null, function(error) {
console.error('Failed to load:', error);
});
</script>