```kotlin val mutableList = mutableListOf<Int>() ``` 或者 ```kotlin val mutableList = listOf(1, 2, 3).toMutableList() ``` 2.使用add方法向列表中添加元素。在Kotlin中,add方法用于将指定的元素添加到列表的末尾。 示例代码: ```kotlin mutableList.add(4) mutableList.add(5) ``` 在上述示例...
object DataRepository { var data = listOf(1,2,3) } 1. 2. 3. 对象声明的特点是object关键字后面跟着一个名称。就像声明一个变量那样,但是对象声明不是一个表达式,不能把对象声明放在赋值语句的右边。 利用AndroidStudio 的 Show Kotlin Bytecode 功能,看一下对应的 .java 文件: public final class DataR...
if (data.list != null) { mDataList.addAll(data.list) } 1. 2. 3. 原因 Kotlin不允许往集合中添加null值,虽然签名做了空判断,但是怕在调用addAll时对应值仍然被修改为null(脑子有问题)。 解决方案 方式1. data.list?.let(mDataList::addAll) 方式2. data.list?.let { n...
In this article, we’ve explored various ways of addingListcontents into aSetin Kotlin. First, we discussed a programmatic approach that simply iterates aListand adds each element to aSet. Furthermore, we looked at other approaches that make use of Kotlin in-built methods such asaddAll()and...
If we come from the Java world, these lists may confuse us. Also, when we try to add an element to a list in Kotlin, it’s not always as straightforward as calling theadd()method in Java. For example, sometimes, thelist.add()line may not compile. ...
Kotlin可以编译成Java字节码，也可以编译成JavaScript，方便在没有JVM的设备上运行。 JetBrains，作为目前...
implementation("io.github.zxing-cpp:kotlin-native:2.2.1") ``` to your `build.gradle.kts` file in the `dependencies` section of `nativeMain` source set. ## Use A trivial use case looks like this: ```kotlin import zxingcpp.BarcodeFormat import zxingcpp.BarcodeReader import zxingcpp.ImageFo...
In Kotlin, as in every language, we have predefined operators to perform certain operations. The most typical are the addition (+), subtraction (-), multiplication (*) or division (/), but there are a few more. In some languages, such as Java, these operators are limited to certain ...
怎么样在recyclerview 里添加header Kotlin classAllCategoryAdapter(val categoryList : List<AllCategoryBean>) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {privateval TYPE_HEADER : Int = 0privateval TYPE_LIST : Int = 1override fun getItemViewType(position: Int): Int {if(position == 0) ...
Use the latest version of ArcGIS Maps SDK for Kotlin to build mobile apps that incorporate capabilities such as mapping, geocoding, routing, geoprocessing, and other spatial analysis.