深圳大数据培训学习：方法的嵌套--【千锋】
方法里嵌套定义其他方法
示例1
object EmbedDemo { def add3(x:Int,y:Int,z:Int)={ def add2(x:Int,y:Int)={ x y } add2(add2(x,y),z) } def main(args: Array[String]): Unit = { println(add3(1,2,3)) //6 } }
示例2
def factorial(x: Int): Int = { def fact(x: Int, accumulator: Int): Int = { if (x <= 1) accumulator else fact(x - 1, x * accumulator) } fact(x, 1) } println("Factorial of 2: " factorial(2)) println("Factorial of 3: " factorial(3))
方法的多态
Scala里方法可以通过类型实现参数化，类似泛型。
def listOfDuplicates[A](x: A, length: Int): List[A] = { if (length < 1) Nil else x :: listOfDuplicates(x, length - 1) } println(listOfDuplicates[Int](3, 4)) // List(3, 3, 3, 3) println(listOfDuplicates("La", 8)) // List(La, La, La, La, La, La, La, La)
