let input = "We start by HTML, CSS, JavaScript, JSON and REST.Later we touch some PHP, MySQL and SQL. " +
    "Later we play with C#, EF, SQL Server and ASP.NET MVC.Finally, we touch some Java, Hibernate and Spring.MVC.";

printUppercaseWords(input);

function printUppercaseWords(input) {
    let result = input.match(/\b[A-Z]+\b/g);
    console.log(result.join(', '));
}