fun main(args: Array) {

val alist = arrayListOf
    
     (1,2,3,4)val blist = arrayListOf
     
      ("a","dd", "","e")alist.forEach {    it -> println(it)}//这种写法是函数引用,要求类型一致alist.forEach(::println)val vistor=Vistor()val x = vistor::helloprintln(x("mike"))val a = "abc"a.isNotEmpty()复制代码
     
    

public inline fun Iterable.filter(predicate: (T) -> Boolean): List

{

return filterTo(ArrayList
    
     (), predicate)复制代码
    

}

//filter需要一个参数， 这个参数是一个函数，函数的类型是 一个参数T，返回Boolean类型的函数//String::isNotEmpty隐含一个参数，就是调用实例对象的本身，真正调用的是 xx.isNotEmpty()blist.filter(String::isNotEmpty)val pdfPrinter = PdfPrinter()blist.forEach(pdfPrinter::printPdf)复制代码

}

class PdfPrinter(){ fun printPdf(any: Any){ println(any) } }

class Vistor { fun hello(name:String){ println("hello $name") } }