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！