Java - menu loop and math calculations -

i'm working on program give user menu, allow them select option, ask different numbers calculation based on menu choice. i've started basic outline of program, need getting loops implemented , working.

here code far:

import java.util.scanner;  public class lb04alexander {  public static void main(string[] args) {     scanner input = new scanner(system.in);     system.out.println("this program perform several types of calculations.");     system.out.println();     system.out.println("-menu-");     system.out.println("select following menu options:");     system.out.println("1 - compute integer powers of number");     system.out.println("2 - compute factorial");     system.out.println("3 - compute square root");     system.out.println("4 - compute cube root");     system.out.println("5 - compute exponential");     system.out.println("6 - compute sine of angle");     system.out.println("7 - compute cosine of angle");     system.out.println("8 - convert positive integer binary");     system.out.println("9 - exit");     system.out.println("please enter number corresponding choice:");      int menuchoice = input.nextint();     while (menuchoice >= 1 && menuchoice <= 9); {         switch (menuchoice) {         case 1:             system.out.println("you have chosen compute integer powers of number.");             system.out.println("please enter number base:");             double base1 = input.nextdouble();             system.out.println("now, enter non-negative integer exponent:");             int exponent1 = input.nextint();             if (exponent1 < 0)                 system.out.println("error: exponent negitive.");             else                 system.out.println(base1 + "^" + exponent1 + " = " + "");             break;         case 2:             system.out.println("you have chosen compute factorial (n!) of non-negative integer.");             system.out.println("please enter non-negitive integer n:");             long fact = input.nextlong();             int result = 1;              if (fact < 0)                  system.out.println("error: integer negitive.");             else if (fact >= 127)                 system.out.println("error: answer large calculate");             else                 (int = 1; <= fact; i++) {                     result = result * i;                 }             system.out.println(fact + "! = " + result );             break;         case 3:             system.out.println("you have chosen compute square root.");             break;         case 4:             system.out.println("you have chosen compute cube root.");             break;         case 5:             system.out.println("you have chosen compute exponential.");                break;         case 6:             system.out.println("you have chosen compute sine of angle.");              break;         case 7:             system.out.println("you have chosen compute cosine of angle.");                break;         case 8:             system.out.println("you have chosen convert positive integer binary");               break;         case 9:             system.out.println("you have chosen exit");             system.out.println("program lb04alexander terminating...");             input.close();             system.out.println("the program has ended. goodbye.");             break;         default:             system.out.println("invalid menu choice, please try again.");             break;          } }   } } 

the first problem i'm having getting menu loop right way. either doesn't work, or loops forever.

while (menuchoice >= 1 && menuchoice <= 9); 

get rid of semi-colon. when choice satisfies condition, loops forever. when doesn't, quit (since none of cases match) after printing out invalid menu choice, please try again..