Method Overloading

Let us see what Method Overloading is in java & how do we use it…
  • Two or more methods in a class can have the same name, if their argument lists are different

  • Argument list could differ in –
  • Number of parameters
  • Data type of parameters
  • Sequence of data type of parameters
  • This feature we call it as Method Overloading/Static Polymorphism
  • Overloading in java occurs when methods in a same class or in child classes shares a same name with a ‘difference in number of arguments’ or ‘difference in argument type’ or both.

Now, let me ask all of you few questions:

  • Can method overloading occur between methods in a parent class and that of the child class?
  • Answer: Yes, absolutely.

  • Does method overloading depend upon the return type of the methods
  • Answer: No.

Method Overloading Examples:
  • Example 1 – Difference in number of parameters

Output:  1st method

  • Example 2 – Another example to show methods in child classes can also have method overloading





Output:  2nd method

      Now, let us see the cases in which Method overloading is not performed
Methods having same name in one class or in child class could not perform method overloading if they are just different in:

1)  Name of argument, and not in number of arguments or type of arguments.
2)  Having different return type only.

  • At this point of time, many of you might be thinking How method overloading helps in java or I can say Why we need method overloading?
      There are 2 points which comes out –
  • It helps in maintaining consistency in method naming, doing same task with just a difference of input parameter.
  • Helps in reducing overhead of remembering the name of different functions for same task, instead what we can do is we can pass different type or number of parameters to a single overloaded method/function.

Example –

public class ABC

public Employee getEmpById(int empId)
public Employee getEmpByName(int empName)
public Employee getEmpByDob(int empDob)

 /*It’s better to overload methods with same functionality, this make the 
code consistent and reduce overhead of remember method names with 
 different type and number of input parameter.*/ 

Instead write the code as –

public class ABC

public Employee getEmp(int empId)
public Employee getEmp(int empName)
public Employee getEmp(int empDob)

        One important point to note:
  • We can overload static and final method in java but we can’t override static method.

At the end, a small refresher on the interview questions related to overloading which might be asked from the java developers –

  • Can main() method be overloaded in java?
  • Answer:  Yes. The main() method can be overload. But if you change the signature of the main method, the entry point for the program will be dimnished.

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