Can two Java methods have same name with different return types

Question

Can two Java methods have the same name with different return type  The return type of the methods are different and they are declared with the same method s name   Is that allowed

User · Answer

Only  if they accept different parameters  If there are no parameters  then you must have different names   int doSomething String s   String doSomething int      this is fine   int doSomething String s   String doSomething String s      this is not

User · Answer

If both methods have same parameter types  but different return type than it is not possible  From Java Language Specification  Java SE 8 Edition    8 4 2  Method Signature      Two methods or constructors  M and N  have the same signature if they have the same name  the same type parameters  if any     8 4 4   and  after adapting the formal parameter types of N to the the type parameters of M  the same formal parameter types    If both methods has different parameter types  so  they have different signature   then it is possible  It is called overloading

User · Answer

If it s in the same class with the equal number of parameters with the same types and order   then it is not possible for example   int methoda String a int b            return b    String methoda String b int c            return b          if the number of parameters and their types is same but order is different then it is possible since it results in method overloading  It means if the method signature is same which includes method name with number of parameters and their types and the order they are defined

User · Answer

Even if it is an old thread  maybe some is interested   If it is an option to you to use the same method inside the same class and archive different return types  use generics  Oracle Lesson Generics  Simple example for generic value holder class   class GenericValue lt T gt      private T myValue     public GenericValue T myValue    this myValue   myValue       public T getVal     return myValue        And use it like this   public class ExampleGenericValue     public static void main String   args        GenericValue lt Integer gt  intVal   new GenericValue lt Integer gt  10       GenericValue lt String gt  strVal   new GenericValue lt String gt   go on             System out format  I   d nS   s n   intVal getVal    strVal getVal                 will result in the following output   I  10 S  go on

User · Answer

No  C   and Java both disallow overloading on a functions s return type  The reason is that overloading on return-type can be confusing  it can be hard for developers to predict which overload will be called   In fact  there are those who argue that any overloading can be confusing in this respect and recommend against it  but even those who favor overloading seem to agree that this particular form is too confusing

User · Answer

The java documentation states      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    See  http   docs oracle com javase tutorial java javaOO methods html

User · Answer

Only if their parameter declarations are different from memory

User · Answer

According the JLS  you cannot however due to a feature bug in the Java 6 7 compiler  Oracle s JDK  OpenJDK  IBM s JDK  you can have different return types for the same method signature if you use generics   public class Main       public static void main String    args            Main  lt Integer gt print            Main  lt Short gt print            Main  lt Byte gt print            Main  lt Void gt print               public static  lt T extends Integer gt  int print             System out println  here - Integer            return 0            public static  lt T extends Short gt  short print             System out println  here - Short            return 0            public static  lt T extends Byte gt  byte print             System out println  here - Byte            return 0            public static  lt T extends Void gt  void print             System out println  here - Void              Prints  here - Integer here - Short here - Byte here - Void   For more details  read my article here

User · Answer

You can have two methods with the same arguments and different return types only if one of the methods is inherited and the return types are compatible   For example   public class A       Object foo     return null       public class B     extends A       String foo     return null

[java] Can two Java methods have same name with different return types?

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