دستور شرطی switch در جاوا (switch statement)

switch(expression){
    case value :
       //Statements
       break; //optional
    case value :
       //Statements
       break; //optional
    //You can have any number of case statements.
    default : //Optional
       //Statements
}

int age = 24;

          switch (age) {
          case 18:
              System.out.println(" you are 18");
              break;
          case 19:
              System.out.println("you are 19");
              break;
          case 20:
              System.out.println("you are 20");
              break;
          case 21:
              System.out.println("you are 21");
              break;
          case 22:
              System.out.println("you are 22");
              break;
          case 23:
              System.out.println("you are 23");
              break;
          case 24:
              System.out.println("you are 24");
              break;
          case 25:
              System.out.println("you are 25");
              break;

          default:
              System.out.println("you are not in 18-25");
              break;

          }

   String grade = "C";

          switch (grade) {
          case "A":
              System.out.println("very good");
              break;
          case "B":
              System.out.println("good");
              break;
          case "C":
              System.out.println("bad");
              break;
          case "D":
              System.out.println("very bad");
              break;
          }