spark的匿名函數(shù)怎么使用

本篇內(nèi)容主要講解“spark的匿名函數(shù)怎么使用”，感興趣的朋友不妨來(lái)看看。本文介紹的方法操作簡(jiǎn)單快捷，實(shí)用性強(qiáng)。下面就讓小編來(lái)帶大家學(xué)習(xí)“spark的匿名函數(shù)怎么使用”吧!

變量與常量

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"
           ^

函數(shù)

scala> def addOne(m:Int):Int = {
     | m+1
     | }
addOne: (m: Int)Int

scala> var a = addOne(4)
a: Int = 5

匿名函數(shù)

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

多行匿名函數(shù)，傳入多個(gè)參數(shù)

scala> def mult = {(x:Int,y:Int)=>
     | var z = x * y
     | z+19
     | }
mult: (Int, Int) => Int

scala> mult(4,5)
res6: Int = 39

對(duì)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，相信大家對(duì)“spark的匿名函數(shù)怎么使用”有了更深的了解，不妨來(lái)實(shí)際操作一番吧！這里是億速云網(wǎng)站，更多相關(guān)內(nèi)容可以進(jìn)入相關(guān)頻道進(jìn)行查詢，關(guān)注我們，繼續(xù)學(xué)習(xí)！