--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Fahad/Scala/Chapter5.sc Sat Oct 25 17:28:56 2014 +0100
@@ -0,0 +1,55 @@
+package greeter
+
+object Chapter5 {
+ println("Welcome to the Scala worksheet") //> Welcome to the Scala worksheet
+
+ /////////////////////////////////////////////////////////////////////////////
+ // CHAPTER 5: FIRST-CLASS FUNCTIONS
+
+ /*
+ // Write a function to sumall integers between two given numbers a and b
+ def sumInts(a: Int, b: Int): Int =
+ if (a > b) 0 else a + sumInts(a + 1, b)
+
+ sumInts(1, 5)
+
+ //Write a function to sum the squares of all integers between two given numbers a and b
+ def square(x: Int): Int = x * x
+ def sumSquares(a: Int, b: Int): Int =
+ if (a > b) 0 else square(a) + sumSquares(a + 1, b)
+
+ square(5)
+
+ //Write a function to sum the powers 2n of all integers n between two given numbers a and b:
+ def powerOfTwo(x: Int): Int = if (x == 0) 1 else 2 * powerOfTwo(x - 1)
+ def sumPowersOfTwo(a: Int, b: Int): Int =
+ if (a > b) 0 else powerOfTwo(a) + sumPowersOfTwo(a + 1, b)
+
+ sumPowersOfTwo(2, 4)
+ */
+
+ def sum(f: Int => Int, a: Int, b: Int): Int =
+ if (a > b) 0 else f(a) + sum(f, a + 1, b) //> sum: (f: Int => Int, a: Int, b: Int)Int
+
+ //def sumInts(a: Int, b: Int): Int = sum(id, a, b)
+ //def sumInts(a: Int, b: Int): Int = sum((x: Int) => x, a, b)
+ def sumInts(a: Int, b: Int): Int = sum(x => x, a, b)
+ //> sumInts: (a: Int, b: Int)Int
+ //def sumSquares(a: Int, b: Int): Int = sum(square, a, b)
+ //def sumSquares(a: Int, b: Int): Int = sum((x: Int) => x * x, a, b)
+ def sumSquares(a: Int, b: Int): Int = sum(x => x * x, a, b)
+ //> sumSquares: (a: Int, b: Int)Int
+ def sumPowersOfTwo(a: Int, b: Int): Int = sum(powerOfTwo, a, b)
+ //> sumPowersOfTwo: (a: Int, b: Int)Int
+
+ def id(x: Int): Int = x //> id: (x: Int)Int
+ def square(x: Int): Int = x * x //> square: (x: Int)Int
+ def powerOfTwo(x: Int): Int = if (x == 0) 1 else 2 * powerOfTwo(x - 1)
+ //> powerOfTwo: (x: Int)Int
+
+ // 5.2: Currying
+
+
+
+
+}
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Fahad/Scala/WorkSheet.sc Sat Oct 25 17:28:56 2014 +0100
@@ -0,0 +1,81 @@
+package greeter
+
+object WorkSheet {
+ println("Welcome to the Scala worksheet") //> Welcome to the Scala worksheet
+
+ val x = 5 //> x : Int = 5
+ def increase(i: Int) = i + 1 //> increase: (i: Int)Int
+ increase(x) //> res0: Int = 6
+
+ // Expressions And Simple Functions
+
+ 87 + 145 //> res1: Int(232) = 232
+ 5 + 2 * 3 //> res2: Int = 11
+
+ "Hello" + " World!" //> res3: String("Hello World!") = Hello World!
+
+ def scale = 5 //> scale: => Int
+ 7 * scale //> res4: Int = 35
+
+ def pi = 3.141592653589793 //> pi: => Double
+ def radius = 10 //> radius: => Int
+ 2 * pi * radius //> res5: Double = 62.83185307179586
+
+ // PARAMETERS
+
+ def square(x: Double) = x * x //> square: (x: Double)Double
+ square(2) //> res6: Double = 4.0
+ square(square(4)) //> res7: Double = 256.0
+
+ def sumOfSquares(x: Double, y: Double) = square(x) + square(y)
+ //> sumOfSquares: (x: Double, y: Double)Double
+ sumOfSquares(3, 2 + 2) //> res8: Double = 25.0
+
+ def loop: Int = loop //> loop: => Int
+ def first(x: Int, y: Int) = x //> first: (x: Int, y: Int)Int
+ def constOne(x: Int, y: => Int) = 1 //> constOne: (x: Int, y: => Int)Int
+ constOne(1, loop) //> res9: Int = 1
+
+ // 4.3 CONDITIONAL EXPRESSIONS
+
+ def abs(x: Double) = if (x >= 5) x + 1 else x - 1
+ //> abs: (x: Double)Double
+ abs(4) //> res10: Double = 3.0
+
+ // 4.4: Square Roots by Newton's Method
+
+ def sqrtIter(guess: Double, x: Double): Double =
+ if (isGoodEnough(guess, x)) guess
+ else sqrtIter(improve(guess, x), x) //> sqrtIter: (guess: Double, x: Double)Double
+
+ def improve(guess: Double, x: Double) =
+ (guess + x / guess) / 2 //> improve: (guess: Double, x: Double)Double
+
+ def isGoodEnough(guess: Double, x: Double) =
+ abs(square(guess) - x) < 0.001 //> isGoodEnough: (guess: Double, x: Double)Boolean
+
+ //def sqrt(x: Double) = sqrtIter(1.0, x)
+ //sqrt(25)
+
+ // 4.5: Nested Functions
+
+ def sqrt(x: Double) = {
+ def sqrtIter(guess: Double): Double =
+ if (isGoodEnough(guess)) guess
+ else sqrtIter(improve(guess))
+ def improve(guess: Double) =
+ (guess + x / guess) / 2
+ def isGoodEnough(guess: Double) =
+ abs(square(guess) - x) < 0.001
+ sqrtIter(1.0)
+ } //> sqrt: (x: Double)Double
+ sqrt(25) //> res11: Double = 1.0
+
+ // 4.6: Tail Recursion
+
+ def gcd(a: Int, b: Int): Int = if (b == 0) a else gcd(b, a % b)
+ //> gcd: (a: Int, b: Int)Int
+
+ gcd(21, 36) //> res12: Int = 3
+
+}
\ No newline at end of file