2、基礎
阿新 • • 發佈:2018-09-27
inter for scala 快捷 style pan until 沒有 import
快捷功能
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補全 Tab鍵
粘貼模式 :paste,退出粘貼模式 ctrl + d
語法
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var 定義變量
val 定義常量,相當於java中的final,不能重復賦值
1 to 10 [ 1, 10 ]
1 until 10 [ 1,10 )
字符串求交集
scala> "hello".intersect("he") res31: String = he
BigInt類型
scala> var b = BigInt(999999999) b: scala.math.BigInt = 999999999 scala> b *= b //scala中沒有 ++ 或 -- 語法 scala> b res33: scala.math.BigInt = 999999998000000001 scala> b *= b scala> b res35: scala.math.BigInt = 999999996000000005999999996000000001
導包
import scala.math._ //此處 _ 表示所有 sqrt(2) //開方 pow(2,3) //冪函數
apply方法,相當於索引
scala> "hello".apply(2) res40: Char = l scala> "hello"(2) res41: Char = l
scala中表達式都有值
scala> var x = 2 x: Int = 2 scala> var y = if(x > 0) 1 else -1 y: Int = 1 scala> vary = if(x < 0) -1 y: AnyVal = () scala> var p = println(123) 123 p: Unit = () //相當於null
最後一個表達式是整個語句的值
scala> var b = {print() ;234} warning: there was one deprecation warning; re-run with -deprecation for details ()b: Int = 234
輸入
scala> var name = readLine("輸入名字:") warning: there was one deprecation warning; re-run with -deprecation for details 輸入名字:name: String = lasdjfonclnvlolfdgolsdfsadfs scala> name res43: String = lasdjfonclnvlolfdgolsdfsadfs
循環:while、for、for高級用法
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>
2、基礎