- What are Classes.
- What are Objects.
- Different ways of creating an Object.
- Can we have a Private Constructor in a Java class.
- Why main() method in java is public static void.
- Multiple main() methods in a java class.
- What are Marker Interfaces and how are they different from normal Interfaces ?
- Overriding equals() method.
- What is the purpose of equals() method and when to use it.
- Contract between equals() and hashCode() methods.
- What is Method Overriding.
- What is Method Overloading.
- Purpose of Final keyword.
- What are static variables.
- What are static blocks.
- Can we override a static method.
- Why strings are mutable.
- Ways to iterate a Collection object.
- What are ClassNotFoundException and NoClassDefFoundError.
- Internal working of HashMap.
- Adding Objects to a HashMap.
- Iterating through a HashMap.
- Internal Working of HashSet.
- How does a TreeSet Works in Java.
- Sorting collection of objects by implementing Comparable Interface.
- Sorting collection of objects by implementing Comparator Interface.
- Exception in thread java.util.ConcurrentModificationException.
- How to remove Object/ null from a Collection.
- Exception in thread "main" java.util.ConcurrentModificationException
Java Reflection API
- What is Reflection API and what is its use.
- How to make object of a class by Reflection API.
- How to get all the constructors declared within a given class.
- How to get all the methods available in a class.
- How to get all the fields declared in a class.
- How to get all packages in the project class path.
- How to check if field of class is final.
- How to check if field of class is static.
- Connect to Mysql Database server using JDBC.
- Generate a Random Number between two given numbers.
- Check if a given number is Armstrong.
- Factorial of a number using Recursion.
- Find the sum of digits of a number.
- Find the sum of digits of a number that are even.
- How to convert a number from one base to another.
- Reverse a given String.
- Reverse each word in a line of a given String.
- Convert a String to Integer without using parseInt() method.
- Find the word with maximum occurrences in a line.
- Find all Permutations and Combinations of a String.
Difference Between Questions
- Difference between Method Overloading and Method Overriding.
- Difference between Enumeration and Iterator.
- Difference between Interface and Abstract Class.
- Difference between Comparable and Comparator Interfaces.
- Difference between HashMap and HashTable.
- Difference between String, String Builder and StringBuffer
- Difference between final and finally.
- Difference between JDK and JRE