Scala是一门多范式的编程语言,运行在JVM虚拟机上,使用起来非常灵活,具有面向对象风格, 函数式风格, 更高层的并发模型等特性,代码量是java的五分之一到十分之一
Scala语言有丰富的循环控制结构,if, for,
Scala的数组、映射、元组
1.数组
定长数组scala>val arr = new Array[Int](4)
变长数组scala>import scala.collection.mutable.ArrayBuffer
scala>val b = ArrayBuffer[Int]()
scala>b + =1
scala>b + =(1,2,3,5)
2.映射
scala>val charInt = Map("hadoop"->11,"spark"->6,"Flink"->5)
3.元组
scala>val tuple=(1,1.2,"c","HelloWorld")
访问元组
scala>tuple._1
scala>tuple._4
4.案例
删除数组中第一个负数后所有的负数
scala> import scala.collection.mutable.ArrayBuffer
scala> var b=ArrayBuffer(1,2,3,-4,4,8,7,-9 ,10)
scala> var i=0
scala> import scala.util.control.Breaks._
scala> var fir= false
scala> a.filter{
| case x if x < 0 && !firstNeg => firstNeg = !firstNeg; true
| case x if x < 0 && firstNeg => false
| case _ => true
| }.foreach(println)