在Scala中可以嵌套定义方法。例如以下对象提供了一个factorial方法来计算给定数值的阶乘：
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))
程序的输出为:
Factorial of 2: 2
Factorial of 3: 6