scala對象簡單記錄
阿新 • • 發佈：2018-07-09
ray 簡單記錄 都在 per t對象 tst bstr err 方法
object Person {
private val eyeNum = 2
def getEyeNum = eyeNum
def main(args: Array[String]): Unit = {
println(Person.getEyeNum) // 2
}
}
abstract class Hello(var message:String) {
def sayHello(name :String)
}
object HelloImpl extends Hello("hello"){
override def sayHello(name: String): Unit = {
println(message + "," + name)
}
def main(args: Array[String]): Unit = {
HelloImpl.sayHello("yxj")
}
}
/**
* 一個類和一個object對象名字相同，都在一個.scala文件中，那麽他們就是伴生類和伴生對象
*
* @param name
* @param age
*/
class People(name:String , age:Int ) {
def sayHello = println("hi," + name +", your age is " + age + ",your eyeNum is " + People.eyeNum)
}
object People {
private val eyeNum = 2
def getEyeNum = eyeNum
}
object objectsTest{
def main(args: Array[String]): Unit = {
val yy = new People("yxj" , 30)
yy.sayHello
}
}
/**
* object中apply方法的使用，簡化對象創建的過程
*
*/
class Apple(name:String ,age:Int) {
println(name + "," + age)
}
object Apple{
// 伴生對象的apply簡化了創建伴生類的方式
def apply(name: String, age: Int): Apple = new Apple(name, age)
def main(args: Array[String]): Unit = {
val a = Apple("yxj" , 30)
println(a)
// 普通的創建類的過程
val a1 = new Apple("yxj" , 31)
// 伴生對象定義了apply後，不需要在使用new關鍵字來創建一個類的對象實例了
}
}
scala對象簡單記錄