Which of these can be used to differentiate two or more methods having same name?

Here is an example of a typical method declaration:

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Naming a Method
Overloading Methods
Can you have two methods with the same name?
What is the correct name of a method which has the same name?
Can we have multiple methods with the same name in the same class?
Which of the following is a method having same name as that of its class?

public double calculateAnswer(double wingSpan, int numberOfEngines,
                              double length, double grossTons) {
    //do the calculation here
}

The only required elements of a method declaration are the method's return type, name, a pair of parentheses, (), and a body between braces, {}.

More generally, method declarations have six components, in order:

Modifiers—such as public, private, and others you will learn about later.
The return type—the data type of the value returned by the method, or void if the method does not return a value.
The method name—the rules for field names apply to method names as well, but the convention is a little different.
The parameter list in parenthesis—a comma-delimited list of input parameters, preceded by their data types, enclosed by parentheses, (). If there are no parameters, you must use empty parentheses.
An exception list—to be discussed later.
The method body, enclosed between braces—the method's code, including the declaration of local variables, goes here.

Modifiers, return types, and parameters will be discussed later in this lesson. Exceptions are discussed in a later lesson.

Definition: Two of the components of a method declaration comprise the method signature—the method's name and the parameter types.

The signature of the method declared above is:

calculateAnswer(double, int, double, double)

Naming a Method

Although a method name can be any legal identifier, code conventions restrict method names. By convention, method names should be a verb in lowercase or a multi-word name that begins with a verb in lowercase, followed by adjectives, nouns, etc. In multi-word names, the first letter of each of the second and following words should be capitalized. Here are some examples:

run
runFast
getBackground
getFinalData
compareTo
setX
isEmpty

Typically, a method has a unique name within its class. However, a method might have the same name as other methods due to method overloading.

Overloading Methods

The Java programming language supports overloading methods, and Java can distinguish between methods with different method signatures. This means that methods within a class can have the same name if they have different parameter lists (there are some qualifications to this that will be discussed in the lesson titled "Interfaces and Inheritance").

Suppose that you have a class that can use calligraphy to draw various types of data (strings, integers, and so on) and that contains a method for drawing each data type. It is cumbersome to use a new name for each method—for example, drawString, drawInteger, drawFloat, and so on. In the Java programming language, you can use the same name for all the drawing methods but pass a different argument list to each method. Thus, the data drawing class might declare four methods named draw, each of which has a different parameter list.

public class DataArtist {
    ...
    public void draw(String s) {
        ...
    }
    public void draw(int i) {
        ...
    }
    public void draw(double f) {
        ...
    }
    public void draw(int i, double f) {
        ...
    }
}

Overloaded methods are differentiated by the number and the type of the arguments passed into the method. In the code sample, draw(String s) and draw(int i) are distinct and unique methods because they require different argument types.

You cannot declare more than one method with the same name and the same number and type of arguments, because the compiler cannot tell them apart.

The compiler does not consider return type when differentiating methods, so you cannot declare two methods with the same signature even if they have a different return type.

Note: Overloaded methods should be used sparingly, as they can make code much less readable.

This set of Java Questions and Answers for Entrance exams on “Methods Taking Parameters”.

1. Which of these is the method which is executed first before execution of any other thing takes place in a program?
a) main method
b) finalize method
c) static method
d) private method

Answer: c
Clarification: If a static method is present in the program then it will be executed first, then main will be executed.

2. What is the process of defining more than one method in a class differentiated by parameters?
a) Function overriding
b) Function overloading
c) Function doubling
d) None of the mentioned

Answer: b
Clarification: Function overloading is a process of defining more than one method in a class with same name differentiated by function signature i:e return type or parameters type and number. Example – int volume(int length, int width) & int volume(int length , int width , int height) can be used to calculate volume.

3. Which of these can be used to differentiate two or more methods having the same name?
a) Parameters data type
b) Number of parameters
c) Return type of method
d) All of the mentioned

Answer: d
Clarification: None.

4. Which of these data type can be used for a method having a return statement in it?
a) void
b) int
c) float
d) both int and float

Answer: d
Clarification: None.

5. Which of these statement is incorrect?
a) Two or more methods with same name can be differentiated on the basis of their parameters data type
b) Two or more method having same name can be differentiated on basis of number of parameters
c) Any already defined method in java library can be defined again in the program with different data type of parameters
d) If a method is returning a value the calling statement must have a variable to store that value

Answer: d
Clarification: Even if a method is returning a value, it is not necessary to store that value.

6. What will be the output of the following Java program?

```
    class box 
```
```
    {
```
```
        int width;
```
```
        int height;
```
```
        int length;
```
```
        int volume;
```

        void volume(int height, int length, int width)

```
        {
```

             volume = width * height * length;

```
        } 
```
```
    }    
```
```
    class Prameterized_method{
```

        public static void main(String args[])

```
        {
```
```
            box obj = new box();
```
```
            obj.height = 1;
```
```
            obj.length = 5;
```
```
            obj.width = 5;
```
```
            obj.volume(3, 2, 1);
```

            System.out.println(obj.volume);

```
        } 
```
```
    }
```

a) 0
b) 1
c) 6
d) 25

Answer: c
Clarification: None
output:

$ Prameterized_method.java
$ Prameterized_method
6

7. What will be the output of the following Java program?

```
    class equality 
```
```
    {
```
```
        int x;
```
```
        int y;
```
```
        boolean isequal()
```
```
        {
```
```
            return(x == y);  
```
```
        } 
```
```
    }    
```
```
    class Output 
```
```
    {
```

        public static void main(String args[])

```
        {
```

            equality obj = new equality();

```
            obj.x = 5;
```
```
            obj.y = 5;
```

            System.out.println(obj.isequal);

```
        } 
```
```
    }
```

a) false
b) true
c) 0
d) 1

Answer: b
Clarification: None
output:

$ javac Output.java
$ java Output 
true

8. What will be the output of the following Java program?

```
    class box 
```
```
    {
```
```
        int width;
```
```
        int height;
```
```
        int length;
```
```
        int volume;
```
```
        void volume() 
```
```
        {
```

            volume = width * height * length;

```
        } 
```
```
        void volume(int x) 
```
```
        {
```
```
            volume = x;
```
```
        }
```
```
    }    
```
```
    class Output 
```
```
    { 
```

        public static void main(String args[])

```
        {
```
```
            box obj = new box();
```
```
            obj.height = 1;
```
```
            obj.length = 5;
```
```
            obj.width = 5;
```
```
            obj.volume(5);
```

            System.out.println(obj.volume);

```
        } 
```
```
    }
```

a) 0
b) 5
c) 25
d) 26

Answer: b
Clarification: None.
output:

$ javac Output.java
$ java Output
5

9. What will be the output of the following Java program?

```
    class Output 
```
```
    {
```

        static void main(String args[])

```
        {    
```
```
             int x , y = 1;
```
```
             x = 10;
```
```
             if(x != 10 && x / 0 == 0)
```
```
                 System.out.println(y);
```
```
             else
```

                 System.out.println(++y);

```
        } 
```
```
    }
```

a) 1
b) 2
c) Runtime Error
d) Compilation Error

Answer: d
Clarification: main() method must be made public. Without main() being public java run time system will not be able to access main() and will not be able to execute the code.
output:

$ javac Output.java
Error: Main method not found in class Output, please define the main method as:
   public static void main(String[] args)

10. What will be the output of the following Java program?

Can you have two methods with the same name?

Two methods may share the same name, provided the number of parameters are different, or if they both have the same parameters, then there is at least one position, i where the parameter types differ.

What is the correct name of a method which has the same name?

The practice of defining more than one method in a class with same name is called method overloading.

Can we have multiple methods with the same name in the same class?

Yes, we can define multiple methods in a class with the same name but with different types of parameters. Which method is to get invoked will depend upon the parameters passed.

Which of the following is a method having same name as that of its class?

Which of the following is a method having same name as that of it's class? Explanation: A constructor is a method that initializes an object immediately upon creation. It has the same name as that of class in which it resides.

Cryto Eth

Which of these can be used to differentiate two or more methods having same name?

Naming a Method

Overloading Methods

Can you have two methods with the same name?

What is the correct name of a method which has the same name?

Can we have multiple methods with the same name in the same class?

Which of the following is a method having same name as that of its class?

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