ChoiceMenu.java

//Использовать оператор цикла do-while для выбора пункта меню.
package Chapter05;

public class ChoiceMenu {
    public static void main(String[] args)
            throws java.io.IOException{
        char choice;
        do {
            System.out.println("Справка по оператору.");
            System.out.println("   1. if");
            System.out.println("   2. switch");
            System.out.println("   3. while");
            System.out.println("   4. do-while");
            System.out.println("   5. for\n");
            System.out.println("Выберите нужный пункт:");
            choice = (char) System.in.read();
        }   while (choice < '1' || choice > '5');
        System.out.println("\n");
        switch(choice) {
            case '1' :
                System.out .println ( "if: \n");
                System.out.println("if(ycлoвиe) оператор;");
                System.out.println("else оператор;");
                break;
            case '2' :
                System.out.println("switch:\n");
                System.out .println( "switсh(выражение) {");
                System.out.println(" case константа:");
                System.out.println(
                        " последовательность операторов");
                System.out.println(" break;");
                System. out .println (" / / ... ");
                System.out.println("}");
                break;
            case '3' :
                System.out.println("while:\n");
                System.out.println("while(ycлoвиe) оператор;");
                break;
            case '4' :
                System.out.println("do-while:\n");
                System.out.println("do {");
                System.out.println(" оператор;");
                System.out.println("} while (условие);");
                break;
            case '5' :
                System.out.println("for:\n");
                System.out.print("for(инициaлизaция; условие; итерация)");
                System.out.println(" оператор;");
                break;
        }

    }
}