learning scala read from console

控制台输入语句：

　　readInt, readDouble, readByte, readShort, readLong, readChar, readBoolean, readLine

example:
scala> import io.StdIn._
import io.StdIn._

scala> var i=readInt()
2
i: Int = 2

scala> var f=readFloat()
2.2
f: Float = 2.2

scala> var b=readBoolean()
true
b: Boolean = true

scala> var str=readLine("please input your name")
please input your namepanzidong
str: String = panzidong