extend to the number

isN.js

// is Number this = global scope (window)
if(typeof this.isN != "function" && (this.constructor.name).toLowerCase() === "window") {
    this.isN = function (...args) {
       		let newArgs = [];
            newArgs = args.map((e) => {
               return !isNaN(e)
            });	
        	return newArgs;
    };
}