Ferguson Enterprises Interview Questions and Answers

Constructor is a special method used to initialize objects. Constructor overloading is creating multiple constructors with different parameters.

• Constructor is called when an object is created

• It has the same name as the class

• It can be overloaded by creating multiple constructors with different parameters

• Constructor overloading allows creating objects with different initial values

• Example: public class Person { public Person() {} public Person(String name) {} }

Typecasting is converting one data type to another. JVM is a virtual machine that executes Java bytecode. JIT is a part of JVM that compiles bytecode to machine code at runtime.

• Typecasting is done using casting operators like (int), (float), etc.

• JVM stands for Java Virtual Machine and is responsible for executing Java bytecode.

• JIT stands for Just-In-Time compiler and is a part of JVM that compiles bytecode to machine code at runtime.

• JIT improves the performance of Java progra...read more

String constant pool is a part of heap memory where Java stores string literals to optimize memory usage.

• String constant pool is a cache of string literals created by the JVM.

• String literals are stored in the pool to optimize memory usage.

• When a new string literal is created, the JVM first checks if it already exists in the pool.

• If it does, a reference to the existing string is returned. If not, a new string is created and added to the pool.

• Heap memory is where objects are st...read more

Class loader loads classes into JVM while wrapper class wraps primitive data types into objects.

• Class loader is responsible for loading classes into JVM at runtime.

• It searches for the class file in the classpath and loads it into memory.

• Wrapper classes are used to wrap primitive data types into objects.

• They provide utility methods to perform operations on primitive data types.

• For example, Integer class wraps int data type and provides methods like parseInt() and toString().

Java is a popular language with strong community support and cross-platform compatibility.

• Java is object-oriented and has automatic memory management

• Other languages like C++ require manual memory management

• Java has a large standard library and is used for web development, mobile apps, and enterprise software

• Other languages like Python are popular for data science and machine learning

• Java is compiled to bytecode and runs on a virtual machine, making it cross-platform compatibl...read more