const reg = /ab+/;

const reg = new RegExp('ab+', flag);

Input : '^Ge'
Output: ["Ge"]
        0: "Ge" 
Input : '[A-z]+'
Output: (3) ["Geeks", "For", "Geeks"]
        0: "Geeks"
        1: "For"
2: "Geeks" 

const str = "Geeks for Geeks";
// Input from User
const regex = prompt("Enter RegExp");
// Conversion from string to RegExp
const reg = new RegExp(regex, "g");
 
// The match fn returns the array of strings 
// That match to RegExp
const result = str.match(reg);
 
if (result) console.log(result);
else console.log("Not Found");

const userInput = prompt("Enter a regular expression pattern:");
const regex = new RegExp(userInput);
console.log(regex);