Kotlin  filterIsInstance filterNotNull forEach

 

fun main(args: Array<String>) {
    val i1 = MyItem(1, 1)
    val i2: MyItem? = null
    val i3: Int = 3
    val i4 = "4"
    val i5 = null
    val i6 = MyItem(6, 6)

    val list = mutableListOf<Any?>(i1, i2, i3, i4, i5, i6)
    list.filterIsInstance(MyItem::class.java).forEach {
        println(it)
    }

    println("---")

    list.filterNotNull().forEach {
        println(it)
    }
}

class MyItem {
    private var id = -1
    private var pos = -1

    constructor(id: Int, pos: Int) {
        this.id = id
        this.pos = pos
    }

    override fun toString(): String {
        return "id=${id} pos=${pos}"
    }
}

 

 

 

 

 

id=1 pos=1
id=6 pos=6
---
id=1 pos=1
3
4
id=6 pos=6

 

 

 

 

Kotlin HashMap entries.filter过滤forEach_kotlin map.entries.foreach-CSDN博客文章浏览阅读997次。一、flow ,emit,onCompletion,collect。四、map，重组改写数据。八、conflate 合并。九、debounce去重。二、函数作为flow。kotlin协程flow filter map flowOn zip combine（1）_zhangphil的博客-CSDN博客。_kotlin map.entries.foreachhttps://blog.csdn.net/zhangphil/article/details/133990762