2、基础

快捷功能

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补全　　Tab键

粘贴模式　　:paste，退出粘贴模式 ctrl + d

语法

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var　　定义变量

val　　定义常量，相当于java中的final，不能重复赋值

1 to 10　　[ 1, 10 ]

1 until 10　　[ 1,10 )

字符串求交集

scala> "hello".intersect("he")
res31: String = he

BigInt类型

scala> var b = BigInt(999999999)
b: scala.math.BigInt = 999999999

scala> b *= b　　　　//scala中没有 ++ 或 -- 语法

scala> b
res33: scala.math.BigInt = 999999998000000001

scala> b *= b

scala> b
res35: scala.math.BigInt = 999999996000000005999999996000000001

导包

import scala.math._　　//此处 _ 表示所有
sqrt(2)               //开方
pow(2,3)              //幂函数

apply方法，相当于索引

scala> "hello".apply(2)
res40: Char = l

scala> "hello"(2)
res41: Char = l

scala中表达式都有值

scala> var x = 2
x: Int = 2

scala> var y = if(x > 0) 1 else -1
y: Int = 1

scala> var y = if(x < 0) -1
y: AnyVal = ()

scala> var p = println(123)
123
p: Unit = ()　　//相当于null

最后一个表达式是整个语句的值

scala> var b = {print() ;234}
warning: there was one deprecation warning; re-run with -deprecation for details
()b: Int = 234

输入

scala> var name = readLine("输入名字：")
warning: there was one deprecation warning; re-run with -deprecation for details
输入名字：name: String = lasdjfonclnvlolfdgolsdfsadfs

scala> name
res43: String = lasdjfonclnvlolfdgolsdfsadfs

循环：while、for、for高级用法

break

scala> import scala.util.control.Breaks._
import scala.util.control.Breaks._

scala> for(i <- 1 to 10){
     | println(i)
     | break}
1
scala.util.control.BreakControl

scala>

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