10+ Tele Access E-services Interview Questions and Answers

Implementation of Linked List with add, display, insert at end and delete operations.

• Create a Node class with data and next pointer

• Create a LinkedList class with head pointer

• Add method to add a new node at the end of the list

• Display method to print all nodes in the list

• Insert at end method to insert a new node at the end of the list

• Delete method to delete a node from the list

Static variables can be accessed from non-static methods using an object reference or by making the variable non-static.

• Static variables can be accessed from non-static methods by creating an object of the class containing the static variable.

• Alternatively, the static variable can be made non-static to be accessed directly from a non-static method.

• Attempting to access a static variable directly from a non-static method will result in a compilation error.

Two objects created - one in the string pool and one in the heap.

• String 'a' is created in the string pool, while String 'b' is created in the heap.

• String pool is a special area in the heap memory where strings are stored to increase reusability and save memory.

• Using 'new' keyword always creates a new object in the heap, even if the content is the same as an existing string in the pool.

Only the original string 'Something' will be garbage collected.

• The concat method in Java does not modify the original string, but instead returns a new string with the concatenated value.

• In this case, 'a' remains as 'Something' and a new string 'Something New' is created, but not assigned to any variable.

• Since the new string is not stored in any variable, it will not be garbage collected.

Implement two stacks using a single array without extra space.

• Divide the array into two halves and use one half for each stack.

• Keep track of the top of each stack separately.

• Handle stack overflow and underflow conditions.

• Example: Implementing two stacks for undo and redo operations in a text editor.

Merge and remove duplicates from two sorted arrays without using Collections

• Use two pointers to iterate through both arrays simultaneously

• Compare elements at each pointer and add the smaller one to the result array

• Skip duplicates by checking if the current element is equal to the previous element

Oracle is a multinational computer technology corporation that specializes in developing and marketing database software and technology.

• Oracle is known for its flagship product, the Oracle Database, which is widely used in enterprise applications.

• It also offers a range of other software products, including middleware, application development tools, and cloud services.

• Oracle has a strong presence in the enterprise market and is a major competitor to other database vendors like...read more

Emulate Producer/Consumer Problem using code

• Create a shared buffer between producer and consumer

• Use synchronization mechanisms like mutex or semaphore to control access to the buffer

• Implement producer and consumer functions to add and remove items from the buffer respectively

I appreciate Oracle's robust and reliable software solutions.

• Oracle's software is known for its scalability and performance.

• Their database management system is widely used and trusted by many organizations.

• Oracle's cloud offerings provide a comprehensive suite of services for businesses.

• Their commitment to innovation and staying ahead of industry trends is impressive.

Creating a deadlock involves two or more threads waiting for each other to release a resource they need.

• Create two threads, each trying to lock two resources in a different order

• Ensure that one thread locks resource A first and then tries to lock resource B, while the other thread locks resource B first and then tries to lock resource A

• This will result in a situation where each thread is waiting for the other to release the resource it needs, causing a deadlock

Implement LRU Cache using a data structure like LinkedHashMap in Java

• Use LinkedHashMap to maintain insertion order

• Override removeEldestEntry method to limit cache size

• Update the access order on get and put operations

Calculate the product of all elements in an array except for the element itself.

• Iterate through the array and calculate the product of all elements except the current element.

• Use two separate arrays to store the product of elements to the left and right of the current element.

• Multiply the corresponding elements from the left and right arrays to get the final result.

POJO is a Plain Old Java Object with private fields and public getters/setters, while a Bean is a Java class with private fields and public zero-argument constructors.

• POJO stands for Plain Old Java Object

• POJO has private fields and public getters/setters

• Bean is a Java class with private fields and public zero-argument constructors

• Beans are usually used in Java EE frameworks like Spring for dependency injection

Code to start 5 threads in Java

• Create a class that implements the Runnable interface

• Instantiate 5 objects of the class

• Create 5 threads using the objects and start them

Code to read a file in Java

• Use FileReader and BufferedReader classes to read the file

• Handle exceptions using try-catch blocks

• Close the file after reading using close() method

Singleton pattern ensures a class has only one instance and provides a global point of access to it.

• Ensures a class has only one instance by providing a global access point to it.

• Uses a private constructor to restrict instantiation of the class.

• Provides a static method to access the singleton instance.

• Commonly used in scenarios where only one instance of a class is needed, such as database connections or logging.

• Example: Singleton pattern can be implemented in Java using a pr...read more