使用yield和函数式编程转换数组 //对Array进行转换,获取的还是Aarry val a = Array(1,2,3,4,5) val a2 = for(ele <- a) yield ele * ele //对ArrayBuffer进行转换,获取的还是ArrayBuffer val b = ArrayBuffer[Int]() b+=(1,2,3,4,5) val b2=for(ele <- b) yield ele*ele //结合if守卫, 仅转换需要元素 val a3= for(
在Scala中,Array代表的含义与Java类似,也是长度不可改变的数组.此外,由于Scala与java都是运行在JVM中,双方可以互相调用,因此Scala数组底层实际上是java数组.列如字符串数组java的String[],整数的数组int[]. val a = new Array[Int](10) val a = new Array[String](10) 可以直接使用Array()创建数组,元素类型自动推断 val a = Array("Hello","world&
Scala's object-oriented collections support mutable and immutable type hierarchies. Also support functional higher-order operations such as map, filter, and reduce that let you use expression-oriented programming in collections. Higher-order operatio
1. Variables (1) Three ways to define variables: 1) val refers to define an immutable variable; scala> val x = x: Int = scala> x*x res4: Int = scala> res4 + # use result as a value res6: Int = scala> res4 + res6 res7: Int = scala> x = # x i
1 Loop (1) for (i <- 1 to 3){ # 1 2 3 } (2) for (i <- 1 until 3){ #1 2 } (3)过滤 for (i <- 1 to 10; if i != 3; if i < 8){ # 1 2 4 5 6 7 } (4) yield for 循环中的 yield 会把当前的元素记下来,保存在集合中,循环结束后将返回该集合.Scala 中 for 循环是有返回值的.如果被循环的是 Map,返回的就是 Map,被循环的是 Li