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Java Objective Questions and Answers 1 . Java was first developed in ? [A] 1990 [B] 1991 [C] 1993 [D] 1996 Answer: B. 1991 Explanation: The original and reference implementation Java compilers, virtual machines, and class libraries were developed by Sun from 1991 and first released in 1995.It is intended to let application developers "write once, run anywhere" (WORA), meaning that code that runs on one platform does not need to be recompiled to run on another. 2. 2. The old name of Java was ? [A] J language [B] oak [C] oct [D] None of above Answer: B. oak Explanation: The language was initially called Oak after an oak tree that stood outside Gosling's office; it went by the name Green later, and was later renamed Java, from Java coffee, said to be consumed in large quantities by the language's creators. 3. Which of the following feature is not supported by java ? [A] Multithreading [B] Reflection [C] Operator Overloading [D] Garbage Collection Answer: C. Operator Overloading Explanation: We cannot overload the operators in java but we can overload functions in java 4. Which of the following is not keyword in java ? [A] null [B] import [C] volatile [D] package Answer: A. null Explanation: null is not a keyword in java. It is a literal value 5. What is the full form of JDK ? [A] Java Data Kit [B] Java Defination Kit [C] Java Development Kit [D] Java Design Kit Answer: C. Java Development Kit Explanation: it's the full featured Software Development Kit for Java, including JRE, and the compilers and tools (like Java Doc, and Java Debugger) to create and compile programs. 6. Which command is used to compile a java program ? [A] javac [B] java [C] javad [D] .javadoc Answer: A. javac Explanation: The javac command in Java compiles a program from a command prompt. It reads a Java source program from a text file and creates a compiled Java class file. The basic form of the javac command is "javac filename " 7. What is the full form of JVM [A] Java Virtual Machine [B] Java Variable Machine [C] Java Virtual Mechanism [D] Java Variable Mechanism Answer: A. Java Virtual Machine Explanation: A Java virtual machine (JVM) is a virtual machine that can execute Java bytecode. It is the code execution component of the Java platform. 8. What is the full form of ADT ? [A] Abstract Data Type [B] Abstract Development tool [C] Abstract Design Tool [D] Advance Development Tool Answer: A. Abstract Data Type Explanation: In computer science, an abstract data type (ADT) is a mathematical model for a certain class of data structures that have similar behavior; or for certain data types of one or more programming languages that have similar semantics. 9. The expected signature of the main method is public static void main(). What happens if we make a mistake and forget to put the static keyword ? [A] The JVM issues an error saying that main method should be declared static [B] The compiler issues a warning saying that main method should be declared static and adds it automati [C] The JVM successfully invokes the main method [D] The JVM fails at runtime with NoSuchMethodError Answer: D. The JVM fails at runtime with NoSuchMethodError Explanation: There is nothing special about the main method and the compiler compiles it like any other method, so it issues no warning or error. The JVM looks for the static main method with the expected signature, and since the static main method is missing, so it throws exception NoSuchMehodError and terminates 10. What does the AWT stands for ? [A] Abstract Windowing toolkit [B] A web toolkit [C] Application with types [D] Absolutly wonderfull toolkit Answer: A. Abstract Windowing toolkit Explanation: AWT is the original user interface provided in java.The AWT classes are provided in java.awt package _____________