LIVING ON MIND

As you can see, this version of OverloadDemo does not define test(int). Therefore, when test( ) is called with an integer argument inside Overload, no matching method is found. However, Java can automatically convert an integer into a double, and this conversion can be used to resolve the call. Therefore, after test(int) is not found, Java elevates i to double and then calls test(double). Of course, if test(int) had been defined, it would have been called instead. Java will employ its automatic type conversions only if no exact match is found.Method overloading supports polymorphism because it is one way that Java implements the "one interface, multiple methods" paradigm. To understand how, consider the following. In languages that do not support method overloading, each method must be given a unique name. However, frequently you will want to implement essentially the same method for different types of data. Consider the absolute value function. In languages that do not support overloading, there are usually three or more versions of this function, each with a slightly different name. For instance, in C, the function abs( )  returns the absolute value of an integer, labs( ) returns the absolute value of a long integer, and fabs()returns the absolute value of a floating-point value. Since C does not support overloading, each function has to have its own name, even though all three functions do essentially the same thing. This makes the situation more complex, conceptually, than it actually is. Although the underlying concept of each function is the same, you still have three names to remember. This situation does not occur in Java, because each absolute value method can use the same name. Indeed, Java's standard class library includes an absolute value method, called abs( ). This method is overloaded  by Java's Math class to handle all numeric types. Java determines which version of abs() to call based upon the type of argument.The value of overloading is that it allows related methods to be accessed by use of a common name. Thus, the name abs represents the general action which is being performed. It is left to the compiler to choose the right specific version for a particular circumstance. You, the programmer, need only remember the general operation being performed. Through the application of polymorphism, several names have been reduced to one. Although this example is fairly simple, if you expand the concept, you can see how overloading can help you manage greater complexity.When you overload a method, each version of that method can perform any activity you desire. There is no rule stating that overloaded methods must relate to one another. However, from a stylistic point of view, method overloading implies a relationship. Thus, while you can use the same name to overload unrelated methods, you should not. For example, you could use the name sqr to create methods that return the square of an integer and the square root of a floating-point value. But these two operations are fundamentally different. Applying method overloading in this manner,feats its original purpose. In practice, you should only overload closely related operations.