Question

请帮助我理解。

我的问题：
我在类构造函数中有N个参数（查看下面的Email类），
1.如何创建多个辅助构造函数？
2.如何将方法值传递给构造函数参数？

class Email (
  private val firstName: String,
  private val lastName: String,
  private val domain: String,
  private var emailCapacity,
  private var alterEmail,
  private var chngPassword){

   ....

  }

Answer 1

我想通过＆＃34;辅助构造函数＆＃34;你的意思是重载 - 在这种情况下，你可以为某些参数提供默认值，例如。

class Email (
  private val firstName: String,
  private val lastName: String,
  private val domain: String,
  private val emailCapacity=100,
  private val alterEmail=false,
  private val chngPassword=true)

然后您可以像val em=new Email("a","b","mydomain.com",alterEmail=true)

一样调用它

Answer 2

您还可以按如下方式创建辅助构造函数：

class Email private (firstname: String, lastName: String, domain: String, emailCapacity: String, alterEmail: String, chgpassord: String) {
  def this(firstname: String) = this(firstname, "", "", "", "", "")
}

如果您想降低灵活性并仅允许特定的构造函数，这可能有意义。

具有多个参数的Scala构造函数

2 个答案: