CitiusTech Senior Software Developer Interview Questions and Answers

Functional interfaces provide a single abstract method for functional programming in Java.

• Functional interfaces allow for lambda expressions and method references to be used as instances of the interface.

• Interfaces with multiple abstract methods cannot be used for lambda expressions.

• Example: java.util.function.Function is a functional interface with a single abstract method apply().

Java 8 introduced new features like lambda expressions, streams, functional interfaces, and default methods.

• Lambda expressions: Allows writing concise code by enabling functional programming.

• Streams: Provides a way to work with sequences of elements efficiently.

• Functional interfaces: Interfaces with a single abstract method, used for lambda expressions.

• Default methods: Allows adding new methods to interfaces without br

Yes, one functional interface can extend another interface in Java.

• Functional interfaces can extend other functional interfaces in Java.

• The child interface can have only one abstract method, but can inherit default methods from the parent interface.

• Example: interface Parent { void method1(); } interface Child extends Parent { void method2(); }

There are four divisions in COBOL: Identification Division, Environment Division, Data Division, and Procedure Division.

• Identification Division: Contains program name, author, and date.

• Environment Division: Specifies the hardware and software environment.

• Data Division: Defines the data structures used in the program.

• Procedure Division: Contains the actual program logic.

GDG stands for Generation Data Group in JCL, used to manage related datasets as a single unit.

• GDG is used in JCL to group related datasets together for easier management.

• It allows for easy referencing of datasets within the group using relative generation numbers.

• Example: MYDATA.GDG(+1) refers to the most recent generation in the GDG.

• Example: MYDATA.GDG(-1) refers to the previous generation in the GDG.

Commonly used functional interfaces include Predicate, Consumer, Supplier, and Function.

• Predicate: used for boolean-valued functions of one argument.

• Consumer: used for operations that take in one argument and return no result.

• Supplier: used for operations that take no arguments and return a result.

• Function: used for operations that take in one argument and return a result.