Programming Groovy 2

6.1 Using List

Creating an instance of ​java.util.ArrayList​ is easier in Groovy than in Java. We don’t have to use ​new​ or specify the class name. We can simply list the initial values we want in the ​List​, as shown here:

lst = [1, 3, 4, 1, 8, 9, 2, 6]
println lst
println lst.getClass().name

Let’s look at the ​ArrayList​’s contents and its type, as reported by Groovy:

[1, 3, 4, 1, 8, 9, 2, 6]
java.util.ArrayList

When we declare a list in Groovy, the reference ​lst​ refers to an instance of ​java.util.ArrayList​, as we can see from the previous output.

We can fetch the elements of the ​List​ by using the ​[]​ operator, as shown in the next example:

WorkingWithCollections/CreatingArrayList.groovy ...