Java Interview Questions

•   if(null==null){

System.out.println("Both are equal");
          }else{
System.out.println("Both are not equal");
          }
       
           What is the output for the above code?

          Output : Both are equal.

• Difference between finally and finalize?
• What is cloning? what is deep and shallow cloning? How to do deep cloning?
• How you write the program to read the file?
• which version of java you used?
• What is the difference between encapsulation and polymorphism?
• Can you tell me about oops concepts?
• what is polymorphism? Did you used anywhere in your project?
• Did you work on multi threading in any of the project?
• Can you tell me the scenarios, where you exactly used syncronization?
• What is immutability?
• you know how to make class as immutable object?
• What is garbage collection? Can we invoke the garbage collection explicitly?
• What are collections you used in your project?
• Difference between Hashset and ArrayList?
• How Hashset eliminates duplicates?
• If you try to add duplicate element to the set, what happens?
• what is the difference between java.util.Date and java.sql.Date?
• what is the difference between java null and sql null?
• how hashmap works internally?
• Difference between HashMap and HashTable?
• What is the difference between Array List and Vector?