3、集合
Groovy支持集合、List、Map和数组
（1）Lists
l 下面是创建List的例子，[]表示空List表达式
list = [5, 6, 7, 8] assert list.get(2) == 7 assert list instanceof java.util.List emptyList = [] assert emptyList.size() == 0 emptyList.add(5) assert emptyList.size() == 1 l 每个List表达式都是java.util.List的实现
（2）范围（Ranges）
l Range允许创建连续值的列表
l 由于Range扩展java.util.List，所以Range可以作为List使用
l 使用..的Range是包括两个边界，使用...的Range只包括开始边界，而不包括结束边界
// an inclusive range range = 5..8 assert range.size() == 4 assert range.get(2) == 7 assert range instanceof java.util.List assert range.contains(5) assert range.contains(8) // lets use an exclusive range range = 5...8 assert range.size() == 3 assert range.get(2) == 7 assert range instanceof java.util.List assert range.contains(5) assert ! range.contains(8) l Range可以用于实现java.lang.Comparable的Java对象
// an inclusive range range = 'a'..'d' assert range.size() == 4 assert range.get(2) == 'c' assert range instanceof java.util.List assert range.contains('a')assert range.contains('d')assert ! range.contains('e')l Range可以用于循环遍历
for (i in 1..10) { println "Hello ${i}"} （3）Maps
l 下面是创建Map的例子，[:]表示空Map表达式
map = ["name":"Gromit", "likes":"cheese", "id":1234] assert map.get("name") == "Gromit"assert map.get("id") == 1234assert map instanceof java.util.Map emptyMap = [:] assert emptyMap.size() == 0 emptyMap.put(5, "foo") assert emptyMap.size() == 1 assert emptyMap.get(5) == "foo" l Map可以象beans一样操作，但key值（类似属性名）必须为有效的String标识
map = ["name":"Gromit", "likes":"cheese", "id":1234] assert map.name == "Gromit" assert map.id == 1234 emptyMap = [:] assert emptyMap.size() == 0 emptyMap.foo = 5 assert emptyMap.size() == 1 assert emptyMap.foo == 5 （4）使用下标操作符
l 可以在字符串、Lists、Maps...中使用下标进行索引
text = "nice cheese gromit!" x = text[2] assert x == "c" assert x.class == String sub = text[5..10] assert sub == 'cheese' map = ["name":"Gromit", "likes":"cheese", "id":1234] assert map['name'] == "Gromit" list = [10, 11, 12] answer = list[2] assert answer == 12 list = 100..200 sub = list[1, 3, 20..25, 33] assert sub == [101, 103, 120, 121, 122, 123, 124, 125, 133] l 可以使用下标操作符更新项目
list = ["a", "b", "c"] list[2] = "d" list[0] = list[1] list[3] = 5 assert list == ["b", "b", "d", 5] l 可以使用负索引从最后开始计数
text = "nice cheese gromit!" x = text[-1] assert x == "!" name = text[-7..-2] assert name == "gromit" l 也可以使用向后范围（开始索引大于结束索引），返回的结果是反转的
text = "nice cheese gromit!" name = text[3..1] assert name == "eci" 
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