How to remove all elements in array of Groovy

Code:

class GroovyController {

def index(){
println '-----------------------------------'
def array1 = [1,2,3,4,5]
def array3 = [1,2,8]
println 'Initial array : '+array1
println 'Remove array3 from array1 : '+array1.removeAll(array3)
println 'Afer Remove array3 : '+array1
println 'Remove with closure condition  : '+array1.removeAll{ it > 4 }
println 'After closure condition : '+array1
render ''
}

}

Output:

Initial array : [1, 2, 3, 4, 5]
Remove array3 from array1 : true
Afer Remove array3 : [3, 4, 5]
Remove with closure condition  : true
After closure condition : [3, 4]