JNTU B.Tech IV Year JAVA PROGRAMMING Previous Question Paper (July/August - 2022 - R18)

Java buzzwords represent the core design goals that make the language robust and versatile. The key buzzwords include:

• Simple: Java is designed to be easy to learn by removing complex features like explicit pointers and operator overloading found in C++.
• Object-Oriented: Everything in Java is an object, facilitating modularity and code reuse through encapsulation, inheritance, and polymorphism.
• Platform Independent: Java code is compiled into bytecode, which can run on any device equipped with a Java Virtual Machine (JVM), summarized as 'Write Once, Run Anywhere' (WORA).
• Secure: Java provides a secure environment by eliminating pointers, enforcing strict type checking, and using a security manager to control access to system resources.
• Robust: It emphasizes early checking for possible errors, with features like strong memory management and automatic garbage collection.
• Multithreaded: Java supports concurrent execution, allowing multiple tasks to run simultaneously within a single program.
• Distributed: Java is designed for the internet, providing extensive libraries for handling TCP/IP protocols and remote method invocation.

Java primarily uses Pass-by-Value for parameter passing. The behavior differs based on the data type:

• Pass-by-Value (Primitive Types): When a primitive type (int, char, etc.) is passed, a copy of the value is created. Changes made to the parameter inside the method do not affect the original variable.
• Pass-by-Reference (Objects): When an object is passed, the value of the reference (the memory address) is copied. While the reference itself is passed by value, the method can modify the internal state of the object because both the original and the copy point to the same memory location.

Example:

class Test { void modify(int i, int[] arr) { i = 10; arr[0] = 10; } }

In this example, calling modify(x, array) will leave the original integer x unchanged, but the first element of the array will be updated to 10 because the method operates on the object reference.