做软装找产品上哪个网站,公司域名查询,网络编程软件,中国建筑人才网官方网文章目录 一、集合的使用1、不可变集合2、可变集合3、Map集合 二、集合的排序1、随机排序2、从小到大3、从大到小4、条件排序 一、集合的使用
1、不可变集合 val listString listOfString(one,two,one)println(listString)输出 listOfString(one,two,one)println(listString)输出[one, two, one]// set集合去重val setString setOfString(one,two,one)println(setString)输出[one, two]2、可变集合 val numbers mutableListOfInt(1,2,3,4)numbers.add(6)numbers.removeAt(1)numbers[0]10println(numbers)输出[10, 3, 4, 6]// set集合自动过滤重复元素val hello mutableSetOfString(h,e,l,l,o)hello.remove(o)println(hello)输出:[h, e, l]//集合的加减操作hellosetOf(0,w,o,r,l,d)输出 [h, e, l, 0, w, o, r, d]3、Map集合 val numberMap mapOfString,Int(a to 1,b to 2,c to 3,d to 4)println(keys:${numberMap.keys})println(values:${numberMap.values})if (a in numberMap.keys){}if (2 in numberMap.values){}输出
keys:[a, b, c, d]
values:[1, 2, 3, 4]二、集合的排序
1、随机排序 val number2 mutableListOfInt(12,25,20,56,28)
// 随机排序number2.shuffled()println(随机$number2)输出随机[12, 25, 20, 56, 28]2、从小到大
// 从小到大排序number2.sort()println(小大${number2})输出小大[12, 20, 25, 28, 56]3、从大到小
// 从大到小排序number2.sortedDescending()println(大小${number2.sortedDescending()})输出:大小[56, 28, 25, 20, 12]4、条件排序 data class Language(var name:String,var score:Int)val languageList mutableListOfLanguage()languageList.add(Language(java,88))languageList.add(Language(kotlin,98))languageList.add(Language(c语言,86))languageList.add(Language(python,80))languageList.add(Language(javascript,80))// sortBy单条件排序languageList.sortBy { it.score }println(languageList)输出[Language(namepython, score80), Language(namejavascript, score80), Language(namec语言, score86), Language(namejava, score88), Language(namekotlin, score98)]// sortWith 多条件排序languageList.sortWith(compareBy({it.score},{it.name}))println(languageList)输出[Language(namejavascript, score80), Language(namepython, score80), Language(namec语言, score86), Language(namejava, score88), Language(namekotlin, score98)]
