Battery Smart Interview Questions and Answers

RDBMS is a relational database management system. SQL query to retrieve data is SELECT * FROM table_name;

• RDBMS is a software system used to manage relational databases.

• SQL is a programming language used to manage RDBMS.

• SELECT statement is used to retrieve data from a table.

• The * symbol retrieves all columns from the specified table.

• table_name is the name of the table from which data is to be retrieved.

Exception handling is a mechanism to handle runtime errors and prevent program crashes.

• It allows the program to gracefully handle errors and continue execution.

• C does have a basic form of exception handling using the setjmp() and longjmp() functions.

• Examples of exceptions include divide by zero, null pointer dereference, and file not found errors.

Count the number of words in a user input string.

• Use the split() method to split the string into an array of words.

• Get the length of the array to get the number of words.

• Handle edge cases like leading/trailing spaces and multiple spaces between words.

Fibonacci series program using recursion

• Define a recursive function to calculate Fibonacci series

• Base case: return 0 if n is 0, return 1 if n is 1

• Recursive case: return sum of previous two Fibonacci numbers

Double array real life example: storing student names in different classes

• Each index of the main array represents a different class

• Each sub-array contains the names of students in that class

• Example: [['Alice', 'Bob'], ['Charlie', 'David']]

Java concepts cover a wide range of topics including object-oriented programming, data structures, algorithms, and more.

• Object-oriented programming principles like inheritance, encapsulation, and polymorphism

• Data structures such as arrays, linked lists, stacks, and queues

• Algorithms like sorting, searching, and graph traversal

• Exception handling, multithreading, and networking in Java

• Java collections framework including lists, sets, maps, and queues

Exceptions in Java are events that disrupt the normal flow of program execution, allowing for error handling.

• Java uses a robust exception handling mechanism with try, catch, and finally blocks.

• There are two main types of exceptions: checked exceptions (e.g., IOException) and unchecked exceptions (e.g., NullPointerException).

• Checked exceptions must be either caught or declared in the method signature using 'throws'.

• Unchecked exceptions do not need to be explicitly handled, as ...read more