Groovy: Construct list from another list

There are multiple ways to create a list from another list.

a.   Using Spread operator

b.   Calling the constructors of ArrayList, LinkedList

c.    Adding all the elements of this list explicitly

Using Spread operator

HelloWorld.groovy

evenNumbers = [0, 2, 4, 6]
oddNumbers = [1, 3, 5, 7]
primeNumbers = [2, 3, 5, 7, 11]

allNumbers = [*evenNumbers, *oddNumbers, *primeNumbers]

println allNumbers

Output

[0, 2, 4, 6, 1, 3, 5, 7, 2, 3, 5, 7, 11]

Calling constructors of ArrayList and LinkedList

HelloWorld.groovy

evenNumbers = [0, 2, 4, 6]

list1 = new ArrayList(evenNumbers)
list2 = new LinkedList(evenNumbers)

println "evenNumbers : ${evenNumbers}"
println "list1 : ${list1}"
println "list2 : ${list2}"

Output

evenNumbers : [0, 2, 4, 6]

list1 : [0, 2, 4, 6]

list2 : [0, 2, 4, 6]

Adding all the elements of this list explicitly

HelloWorld.groovy

evenNumbers = [0, 2, 4, 6]

list1 = new ArrayList()
list1.addAll(evenNumbers)

println evenNumbers
println list1

Output

[0, 2, 4, 6]

[0, 2, 4, 6]

Previous                                                 Next                                                 Home