Groovy list

A list is a structure that stores a collection of data items. In Groovy, List saves a series of object references.

Object references in List occupy a position in the sequence and are distinguished by integer indexes.

List text is represented as a series of objects separated by commas and enclosed in square brackets.

The groovy list is indexed using the index operator. The list index starts at 0 and refers to the first element.

The data in a list in groovy can be of any type. The list of collections under java is somewhat different, and the list under java is a collection of data of the same type.

Groovy lists can be nested. F or example, the "aaa" groovy list has a built-in inverse method reverse(). C alling List.reverse can reverse the list. T he groovy list has a sort method built into it. C alling List.sort() enables list sorting. An empty list is represented as an empty collection declared by :

def list1 = []  
def list2 = [1,2,3,4]  
list2.add(12)  
list2.add(12)  
println list1.size()

Several common methods between lists:

1, add:

def list1 = [100, 101]
def list2 = [ 99,98,1]
println list2.plus(list1) //输出结果： [100, 101, 99, 98,1]
// list2.plus(list1) 也可以写成 list2 + list1

2, delete:

def list1 = [12, 13]
def list2 = [11, 2, 33, 12, 13, 16]
println list2.minus(list1) //输出结果： [11, 2, 33, 16]
//list2.minus(list1) 也可以写成 list2 - list1

In this chapter, we'll discuss the list methods available in Groovy.