Scala 入门笔记-方法备忘
list 操作
val list1 = List("hello java", "hello scala hello c", "hi c++") // 空格分隔+压平 val list2 = list1.split(" ").flatten val list3 = list.flatMap(_.split(" ") // 平行计算的求和 val arr = Array(1, 2, 3, 4, 5, 6, 7) // 和线程有关,每个线程计算一部分:((1+2)+(3+4+5)+(6+7)) val res = arr.par.sum // reduce val res2 = arr.reduce(_+_) val res3 = arr.reduceLeft(_+_) val res4 = arr.par.reduce(_+_) // 并行在多线程里面运行 // fold arr.fold(10)(_-_) // 聚合 list 里面有list val list = List(List(1, 2, 3), List(3, 4, 5), List(4, 8, 9)) list.flatten.reduce(_+_) list.aggregate(0)(_+_.sum, _+_) ----------------------- val l1 = List(5, 6, 4, 7) val l2 = List(1, 2, 3, 4) // 并集 l1 union l2 // 交集 l1 intersect l2 // 差集 l1 diff l2