funmain(){// 创建可变列表集合val list=listOf("Tom","Jerry","Jack")// 使用 for in 循环遍历for(nameinlist){println("for : $name")}// 使用 forEach 遍历list.forEach{println("forEach : $it")}// 遍历时获取索引位置list.forEachIndexed{index,s->println("$index : $s")}} 执行结果 ...
十、List 与 Set 之间相互转换 调用List#toSet() 函数 , 可以将 List 集合转为 Set 集合 , 转换过程中会 自动删除重复的元素 ; 调用List#distinct() 函数 调用Set#toList() 函数 , 可以将 Set 集合转为 List 集合 ; 代码示例 : fun main() { val list = listOf("Tom", "Jerry", "Jack", "To...
val values: List<String>? )val parameters = listOf( Parameter("123", "brand", listOf("Nike")), Parameter("3433", "color", listOf("red", "black")), Parameter("22313", "model", listOf("air max")), Parameter("2312", "origin", listOf("USA")), Parameter(null, "size", list...
List<String> list = new ArrayList<String>(); List<Object> objects = list; 1. 2. <? extends T>与< out T> java中的上界通配符,可以使 Java 泛型具有「协变性 」。 <? extends T>: 能够接受指定类及其子类类型的数据 kotlin中的上界通配符:< out T> < out T>:「只能读取不能修改」,这里的...
3. Usemap()to Transform a List of Objects to a List ofString In this section, we’ll see different variants ofmap()function usage to transform a list ofEmployeeto a list of employee names. 3.1. Usingmap()Function Here, we use themap()function to transform a list ofEmployeeinto a lis...
上面说了map和list一样是只读的,可变的map需要使用mutableMap: varmutableMapOf= mutableMapOf<Int,String>() mutableMapOf.putAll(map)//添加整个mapmutableMapOf.put(5,"拉克丝")//添加指定key的valuemutableMapOf.remove(2)//移除元素mutableMapOf.clear()//清空集合 ...
kotlin基础--List、Set、Map kotlinserverless编程算法 调用listOf函数创建集合,我们可以通过和数组一样的方式: "变量[下标]" 来获取元素,或者使用get函数获取 aruba 2021/12/06 6940 你锁不了解的增强 Map 集合 网站网络安全编程算法 在Jdk 8 中 Map 接口提供了一些新的便利的方法。因为在本文中我所提...
Renderers:Transform values into other representations. Renderers are controlled via theRenderersProcessormethod, and you can access it with thenotebook API entry point. The Kotlin kernel iterates through a list of available renderers, trying to find one that can handle the given data. A library...
先定义两个List对象,后面的操作会用到。 1val list = listOf(0,1,2,3,4,5,6,7,8,9)2val mutableList = mutableListOf(0,1,2,3,4,5,6,7,8,9) 2.1 总数操作 测试代码: 1println(list.any { it %2==1})23println(list.all { it %2==1})45println(list.count { it %2==1})67print...
You can also use thesortWith()function to sort a list according to the order specified by the given comparator. The returned value decides the position of the first object relative to the second object. The following example uses theComparatorobject to compare twoMovieobjects, first by their re...