Java Overloading

tag

Java, overloading

source

DT-On Java 8

source

stackify-polymorphism-in-java

Methods

Multiple methods with the same name in the same class Meet one of the requirements below:

• Different number of parameters
• Different types of parameters
• Different order of parameters

Why not distinguish between methods based on return values:

• compile can not determine which method to call when calling a method for its side effect
  • call a method and ignore the return value: int f(int x) called with f(x)

Primitive Arguments

Primitive Types

Widening Conversion

boolean not support casting

• constant value is treated as int
• for all primitive types supporting narrowing, they would be casted to the function with the next larger type
  • void f(short x), void f(int x), void f(long x)
  • a variable byte b = 0, call function f(b)
  • void f(short x) would actually be called
• char is an exception: if it doesn’t find an exact char match, it is promoted to int

Narrowing Conversion

If an argument is wider than what the method expects, explicit narrowing conversion must be performed.