# Scala 2.7.7-final

Version of implementation Scala of programming language Scala

Version of Scala, released on 28 October 2009.

## Examples:

### Hello, World! - Scala (141):

``````object Main {
def main(args: Array[String]) {
println("Hello, World!")
}
}
``````

### Factorial - Scala (142):

This example uses recursive factorial definition.

``````object Factorial {
def factorial(n: Int): Long =
if (n == 0) 1
else n * factorial(n - 1)
def main(args: Array[String]) {
for {i <- List.range(0, 17)}
yield { println(i + "! = " + factorial(i)) }
}
}
``````

### Factorial - Scala (143):

This example uses iterative factorial definition.

``````object Factorial {
def main(args: Array[String]) {
var f = BigInt(1)
format("0! = %s\n", f)
for {i <- 1 to 16} {
f *= i;
format("%s! = %s\n", i, f)
}
}
}
``````

### Fibonacci numbers - Scala (144):

This example uses recursive definition of Fibonacci numbers.

``````object Fibonacci {
def fibonacci(n: Int): Int =
if (n < 3) 1
else fibonacci(n - 1) + fibonacci(n - 2)
def main(args: Array[String]) {
for {i <- List.range(1, 17)}
yield { print(fibonacci(i) + ", ") }
println("...")
}
}
``````

### Fibonacci numbers - Scala (145):

This example shows the usage of lazy evaluations and infinite lists in Scala. Infinite list of Fibonacci numbers is defined using functions `.zip` and `.tail` in the same way as in Haskell example.

``````lazy val fib: Stream[Int] = Stream.cons(1, Stream.cons(1, fib.zip(fib.tail).map(p => p._1 + p._2)))
fib.take(16).print
``````

### Quadratic equation - Scala (230):

This example expands the interactive one with variables input.

``````import java.io.{BufferedReader, InputStreamReader}

object Main {
def main(args: Array[String]) {
solve(A,B,C);
}
def output(real: Double, imag: Double): String =
if (imag == 0) ""+real
else "("+real+","+imag+")"

def solve(A: Int, B: Int, C: Int)
{   if (A == 0) print("Not a quadratic equation.")
else
{   def D = B*B - 4*A*C;
if (D == 0) print("x = "+output(-B/2.0/A, 0));
else if (D > 0)
print("x1 = "+output((-B+Math.sqrt(D))/2.0/A, 0)+"\nx2 = "+output((-B-Math.sqrt(D))/2.0/A, 0));
else print("x1 = "+output(-B/2/A, Math.sqrt(-D)/2.0/A)+"\nx2 = "+output(-B/2/A, -Math.sqrt(-D)/2.0/A));
}
}
}
``````