Generic Methods and Type Inference

Java Tutorials - Herong's Tutorial Examples

∟Generic Methods and Type Inference

This chapter provides tutorial notes and example codes on generic methods and type inference. Topics include what is a generic method; declaring type parameters; specifying type arguments; compiler performing type argument inference; using type parameter in parameterized types.

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What Is a Generic Method

Comparing Generic Method with Non-Generic Method

Non-Generic Method Example - maxNonGeneric()

Generic Method Example - maxGeneric()

Generic Methods in java.util.Collections Class

Testing Generic Methods in Collections Class

What Is Type Argument Inference

Type Argument Inference by Parameter List

Type Argument Inference by Return Value

Generic Methods using Parameterized Types

Parameterized Type as Generic Method Return Type

Conclusion:

A generic method is a method that uses one or more type parameters (also called type variables) to make it more generic so that it can be used as multiple variations.
A generic method has a signature of <A, B, C, ...> SomeType someMethod(...), where <A, B, C, ...> are type parameters.
Type parameters can be bounded as <T extends C & I1 & I2...> to ensure strong typing to reduce runtime type mismatches.
Type arguments can be specified as someObject.<X,Y,...>someMethod(...) when invoking a generic method.
Type argument inference is the process performed by the compiler to determine type arguments if they are not specified in the generic method invocation expression.