Sample run of chapter's interpreter examples
scala> val hex = 0x5 hex: Int = 5 scala> val hex2 = 0x00FF hex2: Int = 255 scala> val magic = 0xcafebabe magic: Int = -889275714
scala> val dec1 = 31 dec1: Int = 31 scala> val dec2 = 255 dec2: Int = 255 scala> val dec3 = 20 dec3: Int = 20
scala> val prog = 0XCAFEBABEL prog: Long = 3405691582 scala> val tower = 35L tower: Long = 35 scala> val of = 31l of: Long = 31
scala> val little: Short = 367 little: Short = 367 scala> val littler: Byte = 38 littler: Byte = 38
scala> val big = 1.2345 big: Double = 1.2345 scala> val bigger = 1.2345e1 bigger: Double = 12.345 scala> val biggerStill = 123E45 biggerStill: Double = 1.23E47
scala> val little = 1.2345F little: Float = 1.2345 scala> val littleBigger = 3e5f littleBigger: Float = 300000.0
scala> val anotherDouble = 3e5 anotherDouble: Double = 300000.0 scala> val yetAnother = 3e5D yetAnother: Double = 300000.0
scala> val a = 'A' a: Char = A
scala> val d = '\u0041' d: Char = A scala> val f = '\u0044' f: Char = D
scala> val B\u0041\u0044 = 1 BAD: Int = 1
scala> val backslash = '\\' backslash: Char = \
scala> val hello = "hello" hello: String = hello
scala> val escapes = "\\\"\'" escapes: String = \"'
// In file basic-types-and-operations/help1.scala println("""Welcome to Ultamix 3000. Type "HELP" for help.""")
Welcome to Ultamix 3000. Type "HELP" for help.
// In file basic-types-and-operations/help2.scala println("""|Welcome to Ultamix 3000. |Type "HELP" for help.""".stripMargin)
Welcome to Ultamix 3000. Type "HELP" for help.
scala> def updateRecordByName(r: Symbol, value: Any) = { | // code goes here | } updateRecordByName: (Symbol,Any)Unit
scala> updateRecordByName(favoriteAlbum, "OK Computer") <console>:6: error: not found: value favoriteAlbum updateRecordByName(favoriteAlbum, "OK Computer") ^
scala> updateRecordByName('favoriteAlbum, "OK Computer")
scala> val s = 'aSymbol s: Symbol = 'aSymbol scala> val nm = s.name nm: String = aSymbol
scala> val bool = true bool: Boolean = true scala> val fool = false fool: Boolean = false
val name = "reader" println(s"Hello, $name!")
scala> s"The answer is ${6 * 7}." res0: String = The answer is 42.
println(raw"No\\\\escape!") // prints: No\z\z\z{\z}escape!
scala> f"${math.Pi}%.5f" res1: String = 3.14159
scala> val pi = "Pi" pi: String = Pi scala> f"pi is approximately {math.Pi}%.8f." res2: String = Pi is approximately 3.14159265.
scala> val sum = 1 + 2 // Scala invokes 1.+(2) sum: Int = 3
scala> val sumMore = 1.+(2) sumMore: Int = 3
scala> val longSum = 1 + 2L // Scala invokes 1.+(2L) longSum: Long = 3
scala> val s = "Hello, world!" s: String = Hello, world! scala> s indexOf 'o' // Scala invokes s.indexOf('o') res0: Int = 4
scala> s indexOf ('o', 5) // Scala invokes s.indexOf('o', 5) res1: Int = 8
scala> -2.0 // Scala invokes (2.0).unary_- res2: Double = -2.0 scala> (2.0).unary_- res3: Double = -2.0
scala> val s = "Hello, world!" s: String = Hello, world! scala> s.toLowerCase res4: String = hello, world!
scala> s toLowerCase res5: String = hello, world!
scala> 1.2 + 2.3 res6: Double = 3.5 scala> 3 - 1 res7: Int = 2 scala> 'b' - 'a' res8: Int = 1 scala> 2L * 3L res9: Long = 6 scala> 11 / 4 res10: Int = 2 scala> 11 % 4 res11: Int = 3 scala> 11.0f / 4.0f res12: Float = 2.75 scala> 11.0 % 4.0 res13: Double = 3.0
scala> math.IEEEremainder(11.0, 4.0) res14: Double = -1.0
scala> val neg = 1 + -3 neg: Int = -2 scala> val y = +3 y: Int = 3 scala> -neg res15: Int = 2
scala> 1 > 2 res16: Boolean = false scala> 1 < 2 res17: Boolean = true scala> 1.0 <= 1.0 res18: Boolean = true scala> 3.5f >= 3.6f res19: Boolean = false scala> 'a' >= 'A' res20: Boolean = true scala> val untrue = !true untrue: Boolean = false
scala> val toBe = true toBe: Boolean = true scala> val question = toBe || !toBe question: Boolean = true scala> val paradox = toBe && !toBe paradox: Boolean = false
scala> def salt() = { println("salt"); false } salt: ()Boolean scala> def pepper() = { println("pepper"); true } pepper: ()Boolean scala> pepper() && salt() pepper salt res21: Boolean = false scala> salt() && pepper() salt res22: Boolean = false
scala> salt() & pepper() salt pepper res23: Boolean = false
scala> 1 & 2 res24: Int = 0 scala> 1 | 2 res25: Int = 3 scala> 1 ^ 3 res26: Int = 2 scala> ~1 res27: Int = -2
scala> -1 >> 31 res28: Int = -1 scala> -1 >>> 31 res29: Int = 1 scala> 1 << 2 res30: Int = 4
scala> 1 == 2 res31: Boolean = false scala> 1 != 2 res32: Boolean = true scala> 2 == 2 res33: Boolean = true
scala> List(1, 2, 3) == List(1, 2, 3) res34: Boolean = true scala> List(1, 2, 3) == List(4, 5, 6) res35: Boolean = false
scala> 1 == 1.0 res36: Boolean = true scala> List(1, 2, 3) == "hello" res37: Boolean = false
scala> List(1, 2, 3) == null res38: Boolean = false scala> null == List(1, 2, 3) res39: Boolean = false
scala> ("he" + "llo") == "hello" res40: Boolean = true
(2 + 2) * 7
scala> 2 << 2 + 2 res41: Int = 32
scala> 2 + 2 << 2 res42: Int = 16
x *= y + 1
x *= (y + 1)
{ val x = a; b.:::(x) }
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