spark的匿名函数怎么使用
本篇内容主要讲解“spark的匿名函数怎么使用”,感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷,实用性强。下面就让小编来带大家学习“spark的匿名函数怎么使用”吧!
变量与常量
scala> var a = addOne(4) a: Int = 5 scala> var a = 123 a: Int = 123 scala> a = 124 a: Int = 124 scala> val b = "demo" b: String = demo scala> b = "demo2" <console>:27: error: reassignment to val b = "demo2" ^
函数
scala> def addOne(m:Int):Int = { | m+1 | } addOne: (m: Int)Int scala> var a = addOne(4) a: Int = 5
匿名函数
scala> (x:Int)=>x+1 res0: Int => Int = <function1> scala> var addOne = (x:Int)=>x+1 addOne: Int => Int = <function1> scala> addOne(3) res1: Int = 4
多行匿名函数,传入多个参数
scala> def mult = {(x:Int,y:Int)=> | var z = x * y | z+19 | } mult: (Int, Int) => Int scala> mult(4,5) res6: Int = 39
对象
scala> class Person{ | var age : Int = 30 | def grow() : Int = { | age =age +1 | age | } | } defined class Person scala> var person = new Person person: Person = $iwC$$iwC$Person@2183cb14 scala> person.grow() res2: Int = 31 scala> person.grow() res3: Int = 32
到此,相信大家对“spark的匿名函数怎么使用”有了更深的了解,不妨来实际操作一番吧!这里是亿速云网站,更多相关内容可以进入相关频道进行查询,关注我们,继续学习!