Closures

A closure is a function that you can pass as an argument to another function.

It is contained by curly brackets, {<closure>}.

You can also define variables before the arrow ->

Tip For more extensive documentation about closures, please refer to the Groovy closure documentation.

Examples

Closure	Purpose
{a, b -> a + b}	Define two variables of an undefined type. Add them up. Show the result.
{String a -> isNotEmpty (a) }	Define a variable of the type String. Apply the validation function isNotEmpty on it. More info: isNotEmpty (value).
{isNotEmpty (it)}	Apply the validation function isNotEmpty on any variable that has it as its name. More info: isNotEmpty (value). Tip Naming an argument is not necessary when there is only one.