Scala 惰性加载

package com.atguigu.chapter04

object Test_Lazy {
  def main(args: Array[String]): Unit = {
    lazy val result : Int = sum(13,12)
    println("1. 函数调用")
    println("2. result = " + result)
  }
  def sum(a: Int ,b:Int):Int = {
    println("3. sum调用！")
    a+b
  }
}