Chendur Construction Interview Questions and Answers

Collection framework provides interfaces and classes to store and manipulate groups of objects. Lists are preferred for ordered collections.

• Lists maintain insertion order and allow duplicates

• Lists provide indexed access to elements

• Lists are suitable for scenarios where elements need to be accessed by index or need to be inserted/removed frequently

Struts is a framework used for developing Java web applications.

• Struts is a framework that implements the Model-View-Controller (MVC) design pattern.

• It provides a set of JSP custom tags to help developers create interactive web applications.

• Struts configuration is typically done using XML files.

• Struts actions are Java classes that handle requests from the user and interact with the model.

• Struts is often used in combination with other technologies like Hibernate or Spring.

• Exam...read more

Yes, SQL is a standard language for managing databases. DDL is for defining structure, DML is for manipulating data.

• DDL stands for Data Definition Language and is used to define the structure of database objects like tables, indexes, etc.

• DML stands for Data Manipulation Language and is used to manipulate data in the database like inserting, updating, deleting records.

• Example of DDL: CREATE TABLE Employees (ID INT, Name VARCHAR(50), Salary DECIMAL(10,2));

• Example of DML: INSERT...read more

Different types of joins in SQL are inner join, left join, right join, and full outer join.

• Inner join: Returns rows when there is at least one match in both tables.

• Left join: Returns all rows from the left table and the matched rows from the right table.

• Right join: Returns all rows from the right table and the matched rows from the left table.

• Full outer join: Returns rows when there is a match in one of the tables.

• Joins are used to combine rows from two or more tables based o...read more

JDK stands for Java Development Kit. Java runs on JDK and no other tool is required.

• JDK is a software development kit used for developing Java applications.

• It includes tools such as Java compiler, JRE, and other development tools.

• Java runs on JDK as it provides all the necessary tools and libraries for compiling, debugging, and running Java programs.

Yes, JSP stands for JavaServer Pages. It is a technology used to create dynamic web pages.

• JSP lifecycle includes translation, compilation, initialization, execution, and destruction phases.

• During translation phase, JSP engine generates a servlet from the JSP page.

• Compilation phase involves compiling the generated servlet into bytecode.

• Initialization phase initializes the servlet, including calling the init() method.

• Execution phase involves processing client requests and gener...read more

Difference between delete vs drop vs truncate

• DELETE is used to remove specific rows from a table

• DROP is used to remove an entire table from the database

• TRUNCATE is used to remove all rows from a table

• DELETE can be rolled back, DROP and TRUNCATE cannot be rolled back

• DELETE is slower than TRUNCATE and DROP

Aggregate functions perform calculations on a set of values and return a single value.

• Used with SELECT statement to return a single value calculated from multiple rows

• Examples include SUM, AVG, COUNT, MAX, MIN

• Can be used with GROUP BY clause to group results by a specific column