The term lambda, which has its roots in lambda calculus, developed by Alonzo Church in 1936, simply refers to an anonymous function. Typically, a function (or method, in more proper Java parlance), is a statically-named artifact in the Java source:
public int add(int x, int y) {
return x + y;
}
This simple method is one named add that takes two int parameters as well as returning an int parameter. With the introduction of lambdas, this can now be written as follows:
(int x, int y) → x + y
Or, more simply as this:
(x, y) → x + y
This abbreviated syntax indicates that we have a function that takes two parameters and returns their sum. Depending on where this lambda is used, the types of the parameters can be inferred by the compiler, ...
