Lambda expressions
The examples in the previous section (that used anonymous classes for the implementation of functional interfaces) looked bulky and felt excessively verbose. For one, there was no need to repeat the interface name, because we had declared it already as the type for the object reference. And, second, in the case of a functional interface that had only one abstract method, there is no need to specify the method name that has to be implemented. The compiler and Java runtime can figure it out. All we need is to provide the new functionality. Lambda expressions were introduced for exactly this purpose.
What is a lambda expression?
The term lambda comes from lambda calculus—a universal model of computation that can be used to simulate any Turing machine. It was introduced by mathematician, Alonzo Church, in the 1930s. A lambda expression is a function, implemented in Java as an anonymous method, that also allows us to omit modifiers, return types, and parameter types. That makes...
