java - Writing an infinite loop -

i writing code should create infinite loop, terminating unexpectedly. when either type in 'y' yes or 'n' no, code should enter non-terminating loop.

import java.util.scanner; import java.text.numberformat; import java.text.decimalformat;  public class math_island_xtended_final {     static scanner sc = new scanner(system.in);     static scanner keyboard = new scanner(system.in);      public static void main(string[] args)     {         //declarations         int bignumber;         int mednumber;         int smallnumber;         double addition;         double subtraction;         double multiplcation;         double division;         double sphere_radius1;         double sphere_radius2;         double sphere_radius3;         double rectangle_measurements;         char repeat;         string input;          system.out.println("welcome math island :d ! ");         system.out.println("we use numbers our formula ! ");         system.out.println("1 rule, no decimals !! ");         system.out.println("please pick # 1 100 now!! ");         bignumber = sc.nextint();                 system.out.print("please pick # 1 20 now!! ");         mednumber = sc.nextint();         system.out.print("please pick # 1 5 now!! ");         smallnumber = sc.nextint();          //results          addition = bignumber + mednumber + smallnumber;         subtraction = bignumber - mednumber - smallnumber;          multiplcation = bignumber * mednumber * smallnumber;         division = bignumber / mednumber / smallnumber;         sphere_radius1 = bignumber * 3.14 * 3.14;         sphere_radius2 = mednumber *  3.14 * 3.14;         sphere_radius3 = smallnumber *  3.14 * 3.14;         rectangle_measurements = bignumber * mednumber * smallnumber;         system.out.println();         system.out.println();          //results 2         system.out.println(" addition answer " + addition);         system.out.println(" subtraction answer " + subtraction);         system.out.println(" multiplcation answer " + multiplcation);         system.out.println(" division answer " + division);         system.out.println(" first sphere answer " + sphere_radius1);         system.out.println(" second sphere answer " + sphere_radius2);         system.out.println(" third sphere answer " + sphere_radius3);         system.out.println(" recangle size  " + rectangle_measurements+ " in cubic feet");         system.out.println();         system.out.println();         system.out.println("would play again  ? ");         system.out.println("y yes, & n  no " );          input = keyboard.nextline();          repeat = input.charat(0);          while (repeat == 'y');             system.out.println();          while (repeat == 'n');             system.out.println();         system.out.println("goodbye!");     }    } 

encase entire code in while loop

define repeat boolean before while loop- set true

then replace

while (repeat == 'y') {       system.out.println(); }  while (repeat == 'n') {       system.out.println();     system.out.println("goodbye!");  }  

with if statement checks if user input "n", in case change repeat false. otherwise keep repeat true.

also- lots of syntax errors in code- clean , should fine