update below code (Currency conversion program) to add loop. (Implement if/else ladder for menu control)

Please tell me how to add loop(while) into the code

1) If the user enters an invalid input the program loop back and allow the user to re-enter input until user input is valid

2) if the user input in the menu is invalid allow the user to re-enter input until user input is valid

*********************************************************************

1. User Input dollar amount
2. verify dollar amount
3. open menu
4. receive user menu selection
5. output if menu is correct
6. loopback to allow the user to make menu until correct

********************************************************************

import java.util.*; public class CurrencyConversion_loop { public static void main(String arg[]) { //Creates an object of Scanner Scanner sc = new Scanner(System.in); System.out.println("Enter 1. Euro Conversion"); System.out.println("Enter 2. Yen Conversion"); System.out.println("Enter 3. Peso Conversion"); System.out.println("Enter 4. Bitcoin Conversion"); System.out.println("Enter 5. All Conversion"); //takes selection's numebr from user System.out.println("Select the number: "); int datal sc.nextInt(); // takes input from user, the funds in dollar System.out.println("Enter funds in dolloar"); double dollars = sc.nextDouble(); double euro = dollars*0.92; double yen dollars*126.65; double peso dollars 19.97; double bitcoin dollars*0.000025; //Varifying the value that user entered. if(datal 1){ } " System.out.println(dollars + "dollars = " + euro + EUROS"); else if(data1 == 2){ } System.out.println(dollars + "dollars = else if(data1 == 3) { } System.out.println(dollars + "dollars = else if(data1 == 4){ } System.out.println(dollars + "dollars = else if(data1 == 5){ System.out.println(dollars + "dollars = System.out.println(dollars + "dollars = System.out.println(dollars + "dollars = System.out.println(dollars + "dollars = " " + yen + YENS"); " + peso + PESOS"); + bitcoin + " BTCS"); " + euro + EUROS"); + yen + "YENS"); + peso + " PESOS"); + bitcoin + " BTCS"); } else { System.out.println("Invalid Input"); sc.close(); } } 3