MindGate Solutions Java Developer Trainee Interview Questions, Process, and Tips

The 4 pillars of OOP are Abstraction, Encapsulation, Inheritance, and Polymorphism.

• Abstraction: Hiding implementation details and showing only necessary information. Example: A car dashboard only shows necessary information like speed, fuel level, etc.

• Encapsulation: Binding data and methods that manipulate the data together. Example: A bank account class with methods to deposit, withdraw, and check balance.

• Inheritance:...read more

Arrays are fixed in size and can store elements of the same type, while collections are dynamic and can store elements of different types.

• Arrays have a fixed length, while collections can grow or shrink dynamically.

• Arrays can only store elements of the same type, while collections can store elements of different types.

• Arrays use indexed access for retrieval and modification, while collections provide various methods fo...read more

Collection is a group of objects while Map is a key-value pair data structure.

• Collection is used to store and manipulate a group of objects.

• Map is used to store and retrieve data based on key-value pairs.

• Collection classes include List, Set, and Queue.

• Map classes include HashMap, TreeMap, and LinkedHashMap.

• Collections allow duplicate elements while Maps do not.

• Example: Collection - List of names, Map - Student ID and c

JDBC steps to connect to a database

• Load the JDBC driver class

• Establish a connection to the database using the DriverManager class

• Create a statement object to execute SQL queries

• Execute the SQL queries and retrieve the results

• Close the statement and connection objects

Multi threading is the concurrent execution of multiple threads in a single program.

• Allows multiple tasks to run concurrently

• Improves performance and responsiveness

• Enables efficient utilization of CPU resources

• Can be used for parallel processing

• Examples: running multiple calculations simultaneously, handling multiple client requests

The life cycle of a thread refers to its various states and transitions during its execution.

• A thread starts in the new state when it is created.

• It moves to the runnable state when it is ready to run but waiting for the CPU.

• When the CPU starts executing the thread, it enters the running state.

• A thread can temporarily move to the blocked or waiting state when it is waiting for a resource or signal.

• A thread can be termin...read more

String is immutable because its value cannot be changed once it is created.

• String objects are stored in the String pool, which is a part of the heap memory.

• When a string is modified, a new string object is created with the modified value.

• Immutable strings are thread-safe and can be safely shared among multiple threads.

• String immutability allows for efficient memory utilization and optimization.