Pramoda Sabat's Blog

JDK 7 and earlier: Avoid using null check in if statement. Use ternary operator for null/exist check and assign a default value before using. This will make the code clear and more understandable as comparable to using multiple if, else   statements. JDK 8 and above : Java-8 provides improved API to deal with object null check. Use isPresent() function available in Java.util.Optional interface for null check of single object. Ex – Employee employee = new Employee(); employee .setName( "Pramoda" ); // Getting optional value Optional<Employee> optionalEmployee = Optional. ofNullable ( employee ) .map(Root::getEmployee); System. out .println( "Is Employee present : + optionalemployee .isPresent()); Use Java.util.Optional functional interface for object null check and assign default value to avoid null pointer exception. Ex – Employee employee = new Employee(); employee .setNa

Scala features The Scala features enables to write efficient programs using both object and functional way but the real power of Scala lies in functional. The functions applies a lots of magic to achieve programming goal. These are following features of Scala:  Object Class Constructor Data Type Access specifiers Operators Operator Overloading Abstract class and Sealed Abstract class Trait and Sealed Trait Inheritance Case class Companion Object Variable declaration Lambda Expression ( X => Y ) Function,  Tail Recursion Scala Function with Value Scala Function with Name Scala Function with Named Arguments Scala function with Variable Arguments Scala function with Default Parameter Scala function with Recursion Higher-order functions Nested Functions Anonymous Functions Scala Partially Applied Functions Currying Functions A bstract function  Closure Option, Some  and  None Either, Left  and  Right Try, Success  and  Failure type, yi

Scala is a multi paradigm programming language used for building scalable application. Applications build on Scala are - Secure, Faster,  Reliable, Resistance to Run time exception About Scala Scala is scalable, functional, immutable and most importantly uses less piece of code to achieve a task. The Scala compiler generates byte code which is identical to that generated by the Java compiler. Scala code can be de-compiled to Java code (With the exception of certain constructor operations). To the JVM, both java code and Scala code looks similar with the only difference is a run time scala-library.jar library. Getting Started with Scala Installation And Setup Download the Java Run time Environment 1.6 or later (1.8 recommended) from - http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html Add the  \bin  directory to the  PATH  system environment variable. Download Scala IDE for Eclipse ( Download Scala IDE ) Create SB

Function : A function is computational unit in a program. Function : To define a function specify - name, parameter, body and return type.   Functions are implicitly declared as abstract if leave off the equal sign and method body. Remove = sign if not to return any thing. A function can have named and optional parameters. Use Unit if the function does not return anything. ( Unit is equivalent to Void in java) Function definition :   def functionName ([list of parameters]) : [ return type ]             Abstract Function :   Ex - def calculation (a:Int, b:String)         Non Abstract Function :    def functionName ([list of parameters]) : [ return type ] = { }              Example -       def calculation ( a : Int, b : Int): Int = {     var sum : Int = 0     sum = a + b     return sum    } Function Recursion: Head  Recursion Tail  Recursion Head  Recursion : It stores result values in stack which may cause stack