Scala--元组

1、tuple元组，里面可以包含各种类型的元素

scala> val t = Tuple3(1,2.03,"Tom")
t: (Int, Double, String) = (1,2.03,Tom)

//这种定义方式需要提前固定元素的个数，有点麻烦

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scala> val t = (1,2.03,"Tom",5)
t: (Int, Double, String, Int) = (1,2.03,Tom,5)

//这种写法就比较好，不需要提前知道元素的个数

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2、访问元组的元素

scala> t.
_1 _3 canEqual equals productArity productIterator toString
_2 _4 copy hashCode productElement productPrefix

scala> t._1
res19: Int = 1

scala> t._2
res20: Double = 2.03

scala> t._4
res21: Int = 5

//通过_x访问元组的元素，下标从1开始

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scala> t.productIterator.foreach(println)
1
2.03
Tom
5

//通过元组的productIterator方法的foreach可以遍历这个元组的各个元素

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