Groovy入門--集合
阿新 • • 發佈:2018-12-04
集合概述
Groovy直接在語言內使用集合。
1.不需要匯入專門的類,也不需要初始化物件。
2.集合是語言本身的本地成員
每個Groovy集合都是java.util.Collection 或 java.util.Map 的事例。
List,String,StringBuffer,Range,Map,File,Matcher都使用統一的size()方法獲取長度
列表一
def toys = [['a','001'],[2,'002'],['c','003']]
println toys.class //輸出:class java.util.ArrayList
assert toys instanceof Collection //無斷言錯誤
println toys[1] //索引從0開始,輸出:[2,"002"]
println toys.get(1) //同上輸出:[2,"002"]
println toys[-2] //同上輸出:[2,"002"]
println toys[1..<2] //輸出:[[2,"002"]]
toys[2] = [3,'003'] //修改第三個元素
println toys[-1 ] //輸出:[3,"003"]
toys.putAt(2,[33,'333'])
println toys[-1] //輸出:[33,"333"]
列表二
toys << [4,'004'] //追加元素
println toys[-1] //輸出:[4,"004"]
toys1 = [1,2,3] //連線列表
toys2 = toy1 + [4,5]
println toys2 //輸出:[1,2,3,4,5]
toys3 = toys2 - [5] //列表中刪除元素
println toys3 //輸出:[1,2,3,4]
列表三
def toy8 = []
toy8 << '11'
toy8 << '22'
toy8 << '33'
toy8 << '44'
println toy8 //輸出:["11","22","33","44"]
toy8 << [8,'008']
println toy8 //輸出:["11","22","33","44",[8,"008"]]
列表List的方法一
def list = [1,2,3,4]
list.add(5) //[1,2,3,4,5]
list.add(2,11) //[1,2,11,3,4,5]
list.addAll([6,7]) //[1,2,11,3,4,5,6,7]
println list.contains(11) //true
println list.containsAll([11,4]) //true
println list.indexOf(11) //2
list.remove(2); println list //[1,2,3,4,5,6,7]
list.removeAll([5,6,7])
println list //[1,2,3,4]
list.clear();println list //[]
列表List的方法二(有些方法會修改原列表,有些方法不修改原列表而產生新的列表)
def fList = [1,2,3,[4,5]]
println fList.flatten() //[1,2,3,4,5],展開後返回新列表
println fList.intersect([3,4,5]) //[3],求交集,返回新列表
println fList.pop() //[4,5],刪除列表最後元素
println fList.reverse() //[3.2.1],反轉列表返回新列表
println fList.sort() //[1,2,3]
def gList = [1,1,2,3,4,3]
println gList.count(3) //輸出:2 有兩個3
對映Map一
def bookMap = [:] //定義空map
println bookMap.getClass() //輸出:class java.util.LinkedHashMap
assert bookMap.size() == 0 //無斷言錯誤
def toyMap = [1:'toy1',2:'toy2']
assert toyMap.containsValue('toy1') //無斷言錯誤
assert toyMap.containsKey(1) //無斷言錯誤
對映Map二
println toyMap //輸出整個Map,[1,"toy1",2:“toy2”]
println toyMap[2] //toy2
println toyMap.get(1) //toy1
toyMap.each(
println toy.key + ':' + toy.value
}//1:toy1 2:toy2
toyMap.each(
println it.key + ':' + it.value
}//使用預設閉包引數it遍歷map,1:toy1 2:toy2
對映Map3
toyMap.put(3,'toy3') //往map中加入元素
println toyMap //[1:"toy1",2:"toy2",3:"toy3"]
toyMap.put(3,'toy333') //鍵已存在,put就變成了修改值
println toyMap //[1:"toy1",2:"toy2",3:"toy333"]
toyMap.remove(3) //刪除map中的元素,引數是鍵
println toyMap //輸出:[1:"toy1",2:"toy2"]
println toyMap.size() //獲取Map大小,輸出:2
println toyMap.keySet() //獲取Map中的key,輸出:[1,2]
println toyMap.values() //輸出:["toy1","toy2"]
println toyMap.values().asList //轉換成ArrayList
println toyMap.values().asList.class //輸出:class java.util.ArrayList
範圍一
def aRange = 1..<5
println aRange //輸出:[1,2,3,4]
println aRange.class //輸出:class groovy.lang.IntRange
println aRange.getClass().getName() //輸出:groovy.lang.IntRange
assert aRange instanceof List //無斷言錯誤
//(1..<5)範圍是IntRange的物件,是特殊的List
範圍二
def bRange = 'a'..<'e'
println bRange //輸出:["a","b","c","d"]
println bRange.class //輸出:class groovy.lang.ObjectRange
assert bRange instanceof List //無斷言錯誤
//('a'..<'e') 是ObjectRange的物件,是特殊的List
範圍三
def cRange = 5..1
println cRange //輸出:[5,4,3,2,1]
def dRange = 'e'..<'a' //輸出:["e","d","c","b"]
//範圍可以使用倒序
範圍Range的方法
println eRange.size() //輸出:10
println eRange.contains(5) //輸出:true
println eRange.get(8) //輸出:9
println eRange.getFrom() //輸出:1
println eRange.getTo() //輸出:10
println eRange.isReverse() //輸出:false
println eRange.subList(3,6) //輸出:[4,5,6]