Scala学习笔记(三)----类的写法

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直接上代码注意点写在注释里了

package cn.limbo.demo  /**    * Created by Limbo on 16/6/28.    * class ClassName(),括号代表了主构造器,def this()表示定义了一个副构造器    * 类中的所有单独可执行的语句都会被包含在主构造器中    */  class Complex(val real: Int, val imaginary: Int) {    def +(operand: Complex): Complex = {      println("Calling + ")      new Complex(real + operand.real, imaginary + operand.imaginary)    }    def *(operand: Complex): Complex = {      println("Calling * ")      new Complex(real * operand.real - imaginary * operand.imaginary, real * operand.imaginary + imaginary * operand.real)    }    def this(real : Int)    {     this(real,1)    }    override def toString(): String = {      real + (if (imaginary < 0) "" else "+") + imaginary + "i";    }  }/**  * Scala继承的时候一定要在构造器中写override在父类的属性前  */class number(override val real:Int ,override val imaginary :Int, var name: String)extends Complex(real,imaginary){  override def toString() : String = super.toString() + "name : " + name}

但是后来发现如果用var来定义属性的话是不能添加override的，原因是可变参数（var定义的参数）没有override的必要，所以若是继承，无需写var，直接写成

class Dog(name:String,age:Int )extends Pet(name, age)

遇到val定义的变量再用override吧

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