void helpon (int what){
        switch(what){
            case '1':
                System.out.println("The if:\n");
                System.out.println("if(condition) statement;");
                System.out.println("else statement;");
                System.out.println("");
                break;
            case '2':
                System.out.println("The switch:\n");
                System.out.println("switch(expression) {");
                System.out.println("    case constant:");
                System.out.println("        case sequence");
                System.out.println("break;");
                System.out.println("    case constant:");
                System.out.println("        case sequence");
                System.out.println("break;");
                System.out.println("}");
                break;
            case '3':
                System.out.println("The for:\n");
                System.out.println("for(initialization; condition; iteration)");
                System.out.println("statement;");
                break;
            case '4':
                System.out.println("The while:\n");
                System.out.println("while(condition){");
                System.out.println("statement;");
                System.out.println("}");
                break;
            case '5':
                System.out.println("The do-while:\n");
                System.out.println("do {");
                System.out.println("    statement;");
                System.out.println("}while(condition);");
                break;
            case '6':
                System.out.println("The break:\n");
                System.out.println("break; or break label;");
                break;
            case '7':
                System.out.println("The continue:\n");
                System.out.println("continue; or continue label;");
                break;
        }
        System.out.println();
    }