Scala——類的定義、重新實現toString方法、檢查先決條件、新增欄位、私有方法、自指向、輔助構造器、操作符、過載、隱式轉換
阿新 • • 發佈：2019-01-26
/**
* Created by jiaoshuhai on 2018/4/23.
*/
//類的建立
class Rational(n:Int,d:Int){//類引數，oject無引數
//檢察先決條件
require(d != 0)
private def gcd(a : Int ,b :Int) : Int =
if(b == 0) a else gcd(b , a % b)
//私有欄位和方法
private val g = gcd(n.abs,d.abs)
// 新增欄位
val number : Int = n / g
val denom : Int = d / g
//重新實現toString方法
override def toString = number + "/" + denom
def add(that: Rational): Rational = {
new Rational(number * that.denom + that.denom,
denom * that.denom)
}
//自指向
def lessthan(that : Rational)={
number * that.denom < that.number * denom //this可以省略
}
//自指向
def max(that :Rational) : Rational ={
if (this.lessthan(that)) that else this //this 不可以省略
}
def this(n:Int) = this(n,1) //輔助構造器，每個輔助構造器都是以this開頭
//定義操作符
def + (that:Rational) : Rational = {
new Rational(number * that.denom + that.denom,
denom * that.denom)
}
// +,*的優先順序誰高，*
def * (that : Rational) : Rational ={
new Rational(number *that.number,denom*that.denom)
}
//方法過載
def * (i : Int) : Rational ={
new Rational(number *i,denom)
}
* Created by jiaoshuhai on 2018/4/23.
*/
//類的建立
class Rational(n:Int,d:Int){//類引數，oject無引數
//檢察先決條件
require(d != 0)
private def gcd(a : Int ,b :Int) : Int =
if(b == 0) a else gcd(b , a % b)
//私有欄位和方法
private val g = gcd(n.abs,d.abs)
// 新增欄位
val number : Int = n / g
val denom : Int = d / g
//重新實現toString方法
override def toString = number + "/" + denom
def add(that: Rational): Rational = {
new Rational(number * that.denom + that.denom,
denom * that.denom)
}
//自指向
def lessthan(that : Rational)={
number * that.denom < that.number * denom //this可以省略
}
//自指向
def max(that :Rational) : Rational ={
if (this.lessthan(that)) that else this //this 不可以省略
}
def this(n:Int) = this(n,1) //輔助構造器，每個輔助構造器都是以this開頭
//定義操作符
def + (that:Rational) : Rational = {
new Rational(number * that.denom + that.denom,
denom * that.denom)
}
// +,*的優先順序誰高，*
def * (that : Rational) : Rational ={
new Rational(number *that.number,denom*that.denom)
}
//方法過載
def * (i : Int) : Rational ={
new Rational(number *i,denom)
}