تمرین متدهای سفارشی در جاوا

                public class Main {
    public static void main(String[] args) {
        
    }

    "" printHelloJava() {
        System.out.println("سلام جاوا");
    }
}

                public class Main {
    public static void main(String[] args) {
        ""
    }

    public static void printHelloJava() {
        System.out.println("سلام جاوا");
    }
}

                public class Main {
    public static void main(String[] args) {
        printString("سلام جاوا");
    }

    public static void printString("") {
        System.out.println(inputString);
    }
}

                public class Main {
    public static void main(String[] args) {
        int result = doubleNumber(5);
        System.out.println(result);
    }

    public static int doubleNumber(int number) {
        int result = number * 2;
        "" result;
    }
}

                public class Main {
    public static void main(String[] args) {
        int result = doubleNumber(5);
        System.out.println(result);
    }

    public static int doubleNumber(int number) {
        "";        
    }
}

                public static boolean isPositive(int number) {
    if (number > 0) {
        return true;
    } else {
        return false;
    }
}

                public class Main {
    public static void main(String[] args) {
        int weight = 3;
        String destination = "international";
        String result = calculateShippingCost(weight, destination);
        System.out.println(result);
    }

    public static String calculateShippingCost("") {
        if (weight <= 0) {
            return "وزن نامعتبر است";
        }

        if (destination.equals("iran")) {
            int shippingCost = 2 * weight;
            return Integer.toString(shippingCost);
        }

        if (destination.equals("international")) {
            int shippingCost = 6 * weight;
            return Integer.toString(shippingCost);
        }

        return "مقصد نامعتبر است";
    }
}

                public class Main {
    public static void main(String[] args) {
        int weight = 3;
        String destination = "international";
        String result = calculateShippingCost(weight, destination);
        System.out.println(result);
    }

    public static String calculateShippingCost(int weight, String destination) {
        if (weight <= 0) {
            return "وزن نامعتبر است";
        }

        if (destination.equals("iran")) {
            int shippingCost = 2 * weight;
            return Integer.toString(shippingCost);
        }

        if (destination.equals("international")) {
            int shippingCost = 6 * weight;
            return Integer.toString(shippingCost);
        }

        return "مقصد نامعتبر است";
    }
}

                public class Main {
    public static void main(String[] args) {
        int number = 20;
        int result = checkNumber(number);
        System.out.println(result);
    }

    public static String checkNumber(int number) {
        if (number > 0) {
            return "عدد مثبت است";
        } else if (number < 0) {
            return "عدد منفی است";
        } else {
            return "عدد صفر است";
        }
    }
}

                public class Main {
    public static void main(String[] args) {
        int number = 0;
        String result = checkNumber(number);
        System.out.println(result);
    }

    public static String checkNumber(int number) {
        if (number > 0) {
            return "عدد مثبت است";
        } else if (number < 0) {
            return "عدد منفی است";
        }
        
        return "عدد صفر است";
    }
}

                public class Main {
    public static void main(String[] args) {
        String firstName = "Emma";
        String lastName = "Smith";
        String separator = "_";
        String result = generateUsername(firstName, lastName, separator);
        System.out.println(result);
    }

    public static String generateUsername(String firstName, String lastName, String separator) {
        String username = firstName + separator + lastName;
        return username;
    }
}

                public class Main {
    public static void main(String[] args) {
        String firstName = "Emma";
        String lastName = "Smith";
        String result = generateUsername(firstName, lastName);
        System.out.println(result);
    }

    public static String generateUsername(String firstName, String lastName) {
        return generateUsername(firstName, lastName, "_");
    }

    public static String generateUsername(String firstName, String lastName, String separator) {
        String username = firstName + separator + lastName;
        return username;
    }
}