Core Java - Questions and Answers (Part -1)
Q1: What are the salient features of Java?
Answer: Some of the features of Java are:
• Java is multi-threaded
• Java has no pointers
• Java has an automatic memory management (garbage collection)
• Java is platform independent
• Java has built-in support for comment documentation
• Java has no operator overloading
• Java doesn’t provide multiple inheritance
• There are no destructors in Java
Q2: Who developed Java language?
Answer: James Gosling
Q3: Which company owns Java now?
Answer: Oracle (since 2010)
Q4: What is the difference between JRE and JDK?
Answer: JRE stands for Java Run-time Environment. It provides libraries and a virtual machine that is required to run a Java program.
JDK stands for Java Development Kit. It consists of java compiler and development libraries to develop java programs. It also includes JRE.
Q5: Name the Java editions available today.
Answer: Java comes in three editions:
1. Java Standard Edition (Java SE) to develop client-side standalone applications or applets.
2. Java Enterprise Edition (Java EE) to develop server-side applications, such as Java servlets, JavaServer Pages (JSP), and JavaServer Faces (JSF).
3. Java Micro Edition (Java ME) to develop applications for mobile devices, such as
Q6: Are java programs platform dependent or independent?
Answer: Platform independent.
Q7: What is Java Virtual Machine (JVM)?
Answer: Java Virtual Machine (JVM) is an abstract machine that executes Java program (compiled into bytecode form). JVM is platform dependent but it makes java program platform independent. There are different JVM for different hardware and software platforms. A JVM loads the java compiled program, verifies and executes it.