javasript

                                    /* Spread syntax ( ex. ...arrayName) allows an iterable such as an array expression or string 
to be expanded in places where zero or more arguments (for function calls) 
elements (for array literals) are expected, or an object expression to be 
expanded in places where zero or more key-value pairs (for object literals) 
are expected. */


//example
function sum(x, y, z) {
  return x + y + z;
}

                                    JavaScript (JS) is a lightweight, interpreted, or just-in-time compiled
programming language with first-class functions.

While it is most well-known as the scripting language for Web pages,
many non-browser environments also use it, such as Node.js, Apache
CouchDB and Adobe Acrobat.

                                    let str = "12345.00";
str = str.substring(0, str.length - 1);
console.log(str);

                                    JavaScript, often abbreviated as JS, is a programming language that conforms
to the ECMAScript specification.
JavaScript is high-level, often just-in-time compiled, and multi-paradigm.
It has curly-bracket syntax, dynamic typing, prototype-based object-orientation,
and first-class functions.