In Java, for a method to accept any number(including zero) of arguments, we can use varargs which has the format myMethod(myType ... myArgumentName).

Configuration

Java Compilation:
Java Runtime:

JDK 11.0.12
JRE HotSpot 11.0.12

In Java, for a method to accept any number(including zero) of arguments, we can use varargs which has the following format:

myMethod(myType ... myArgumentName)

For example:


private static void variableInt(int ... ints) {

    for (int i = 0; i < ints.length; i++) {
        System.out.print("i = " + ints[i] + " ");
    }
    System.out.println("end");
}

Run it in main class:


public class MainClass {

    private static void variableInt(int ... ints) {

        for (int i = 0; i < ints.length; i++) {
            System.out.print("i = " + ints[i] + " ");
        }
        System.out.println("end");
    }

    public static void main(String[] args) {

        variableInt();
        variableInt(2);
        variableInt(3, 5, 6);
    }
}

Output:


end

i = 2 end

i = 3 i = 5 i = 6 end

The data type to be passed in varargs method could be class as well:


public class Person {

    private String name;

    // public setter and getter of all the fields
}

Try with Person class:


public class MainClass {

    private static void variablePerson(Person ... persons) {

        for (int i = 0; i < persons.length; i++) {
            System.out.print("name = " + persons[i].getName() + " ");
        }
        System.out.println("end");
    }

    public static void main(String[] args) {

        Person mary = new Person("Mary");
        Person tom = new Person("Tom");
        Person sam = new Person("Sam");
        Person peter = new Person("Peter");
        Person susan = new Person("Susan");

        variablePerson(mary, tom);
        variablePerson(mary, tom, sam, peter, susan);
    }
}

Output:


name = Mary name = Tom end

name = Mary name = Tom name = Sam name = Peter name = Susan end

Varargs could be used together with other arguments. The only requirement is varargs could only be used as the last argument

for example:


private static void variablePersonWithCount(int count, Person ... persons) {

    for (int i = 0; i <count && i < persons.length; i++) {
        System.out.print("name = " + persons[i].getName() + " ");
    }
    System.out.println("end");
}

Run it in main class:


public class MainClass {

    private static void variablePersonWithCount(int count, Person ... persons) {

        for (int i = 0; i < count && i < persons.length; i++) {
            System.out.print("name = " + persons[i].getName() + " ");
        }
        System.out.println("end");
    }

    public static void main(String[] args) {

        Person mary = new Person("Mary");
        Person tom = new Person("Tom");
        Person sam = new Person("Sam");
        Person peter = new Person("Peter");
        Person susan = new Person("Susan");

        variablePersonWithCount(3, mary, tom);
        variablePersonWithCount(3, mary, tom, sam, peter, susan);
    }
}

Output:


name = Mary name = Tom end

name = Mary name = Tom name = Sam end