Scala的7种值类型和条件表达式以及for循环 Scala的7种值类型和条件表达式

Byte Char Short Int Long Float Double

条件表达式

scala> val x = 3 x: Int = 3scala> val y = if ( x > 1 ) 1 else -1 y: Int = 1scala> println(y) 1scala> val z = if ( x > 1 ) 1 else "error" z: Any = 1scala> val z = if ( x < 1 ) 1 else "error" z: Any = errorscala> val a = if ( x < 1 ) 1 a: AnyVal = ()scala> val a = if ( x < 1 ) 1 else() a: AnyVal = ()scala> val b = if ( x > 1 ) 1 else if ( x < 1 ) -1 else 0 b: Int = 1

for循环

scala> 1 to 10 res1: scala.collection.immutable.Range.Inclusive = Range(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)scala> 1.to(10) res2: scala.collection.immutable.Range.Inclusive = Range(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)scala> 1 until 10 res3: scala.collection.immutable.Range = Range(1, 2, 3, 4, 5, 6, 7, 8, 9)scala> for ( i <- 1 to 10 ) { | println(i) | } 1 2 3 4 5 6 7 8 9 10 scala> val arr = Array("java","scala","python") arr: Array[String] = Array(java, scala, python)scala> for ( i <- arr ) println(i) java scala pythonscala> for ( i <- 1 to 3; j <- 1 to 3 if ( i != j) ) println( i * 10 + j) 12 13 21 23 31 32scala> for ( i <- 1 to 3 ) { | for ( j <- 1 to 3 ) { | if ( i != j ) println( i * 10 + j ) | } | } 12 13 21 23 31 32 scala> val res = for ( i <- 1 until 10 ) yield i res: scala.collection.immutable.IndexedSeq[Int] = Vector(1, 2, 3, 4, 5, 6, 7, 8, 9)scala> println(res) Vector(1, 2, 3, 4, 5, 6, 7, 8, 9)scala> 1.+(3) warning: there were 1 deprecation warning(s); re-run with -deprecation for details res10: Double = 4.0