Android Hybrid Applications Tel Hai October 2012 INFO
During the first semester (winter semester) of the 2012-2013 academic year I deliver an academic course that covers mobile hybrid applications development for the android platform. This course takes place as part of the academic program in computer science that takes place in the Tel Hai college. You can find the google group that was […]
Java EE Platform Tel Hai October 2012 INFO
During the first semester of 2012-2013 academic year I deliver a Java EE course in the Academic Tel Hai college. The official name of that course is ‘Internet Programming’ and it covers the very basic topics in Java EE, including Java Servlets, JSP and JSF. You can find the google group of this course at […]
By Name Parameters in Scala PRO
When calling a function and passing over an argument which is an expression that needs to be evaluated, the expression will be evaluated before the function is invoked and its value will be passed over. This is the default behavior. By adding => in between the parameter name and its type we will defer the […]
Function Type in Scala PRO
Scala allows us to define variables, function parameters and function returned values with a type that is a function. We can even specify the exact signature of that function. import annotation.tailrec object Program { def main(args: Array[String]):Unit = { var func:(Int,Int)=>Int = sum; println(func(4,3)) func = multiply println(func(4,3)) } def sum(a:Int,b:Int):Int = a+b def multiply(a:Int,b:Int):Int […]
Tail Recursive Function in Scala PRO
If the last action a function performs is calling to itself then it is a tail recursive function. When a tail recursive function is executed the computer doesn’t need to keep the memory stack frames. It can use one frame only. Using the @tailrec annotation we can instruct the computer to use one frame only […]
Multiple Lines Expressions in Scala PRO
When having an expression that spans over more than one line the compiler might evaluate the expression while avoiding parts of the expression. We can overcome this problem in two ways. This video clip explains this issue.
Blocks in Scala PRO
The definitions within a block are visible from within the block only. The definitions within a block shadow definitions with the same names that belong to the block’s outer scope. The block has a value just as any other expression. Its value is the value of the last expression it includes. object Program { def […]
Scala Worksheet using IntelliJPRO
The following short video clip shows how to create a Scala worksheet when using the IntelliJ IDE. Using a worksheet we can strength our understanding of the Scala programming language.
The Returned Type of Recursive Function in Scala PRO
When you define a recursive function you must specify the type of the returned value. If you don’t do it the compilation fails. object Program { def main(args: Array[String]):Unit = { println(factorial(4)) } def factorial(num:Int):Int = if (num==0) 1 else num*factorial(num-1) } The following video clip explains that.
Scala Expressions Evaluation PRO
When creating a variable using val or var and assigning the value of an expression into it the expression is evaluated when the variable is created. When creating a function using def and assigning the value of an expression to it the expression is evaluated when calling the function. object Program { def main(args: Array[String]):Unit […]