Functions in functional programming are said to exhibit referential transparency. This means you could replace a function call with its resulting value without changing the computation’s meaning.

In many programming languages, functions cannot be passed around like values, or it takes manual work to have them passed around. Also, data values are immutable in a functional programming language.

When the code implements Java Function with a concise lambda expression runs, the program prints out 25. That’s all you really need to know about the java.util.function.Function interface. It is a ...