Scala Language Type Parameterization (Generics) Parameterized Methods
Example
The return type of a method can depend on the type of the parameter. In this example, x is the parameter, A is the type of x, which is known as the type parameter.
def f[A](x: A): A = x
f(1) // 1
f("two") // "two"
f[Float](3) // 3.0F
Scala will use type inference to determine the return type, which constrains what methods may be called on the parameter. Thus, care must be taken: the following is a compile-time error because * is not defined for every type A:
def g[A](x: A): A = 2 * x // Won't compile
