Packages and Imports

Selective Import

Import a few names from the standard library.

import-math A selective import brings only the listed names into scope. Here `min` and `max` come from `scala.math` and can be called without a prefix.

Selective Import

x
ImportMath.scala
Replay: real traced execution (multi-file project)
import scala.math.{min, max}

object Main {
  def main(args: Array[String]): Unit = {
    val x = 4
    val lo = min(x, 5)
    val hi = max(x, 5)

    println("lo=" + lo)
    println("hi=" + hi)
  }
}

import scala.math.{min, max}

object Main {
  def main(args: Array[String]): Unit = {
    val x = 1
    val lo = min(x, 5)
    val hi = max(x, 5)

    println("lo=" + lo)
    println("hi=" + hi)
  }
}

import scala.math.{min, max}

object Main {
  def main(args: Array[String]): Unit = {
    val x = 9
    val lo = min(x, 5)
    val hi = max(x, 5)

    println("lo=" + lo)
    println("hi=" + hi)
  }
}

  1. x ← 4, lo ← 4, hi ← 5

    3object Main {4  def main(args: Array[String]): Unit = {5    val x→ 4 = 4 //@x=1, 96    val lo→ 4 = min(x4, 5)7    val hi→ 5 = max(x4, 5)89    println("lo=" + lo4)10    println("hi=" + hi5)11  }12}
    outputlo=4
hi=5

  1. x ← 1, lo ← 1, hi ← 5

    3object Main {4  def main(args: Array[String]): Unit = {5    val x→ 1 = 16    val lo→ 1 = min(x1, 5)7    val hi→ 5 = max(x1, 5)89    println("lo=" + lo1)10    println("hi=" + hi5)11  }12}
    outputlo=1
hi=5

  1. x ← 9, lo ← 5, hi ← 9

    3object Main {4  def main(args: Array[String]): Unit = {5    val x→ 9 = 96    val lo→ 5 = min(x9, 5)7    val hi→ 9 = max(x9, 5)89    println("lo=" + lo5)10    println("hi=" + hi9)11  }12}
    outputlo=5
hi=9