10+ Cognizant Trainee Interview Questions and Answers

Answering questions on C compilation stages, linker, and swapping number logic.

• Swapping number logic involves interchanging the values of two variables without using a third variable.

• C compilation stages include preprocessing, compilation, assembly, and linking.

• The linker is a program that combines object files generated by the compiler into a single executable file.

• Example of swapping number logic: int a=5, b=10; a=a+b; b=a-b; a=a-b; //a=10, b=5

A database management system (DBMS) is a software that manages data stored in a database.

• DBMS allows users to create, read, update, and delete data in a database.

• It provides security and access control to prevent unauthorized access to data.

• Examples of DBMS include MySQL, Oracle, Microsoft SQL Server, and MongoDB.

An array is a data structure that stores a collection of elements, each identified by at least one array index or key.

• An array can store elements of the same data type or different data types.

• Arrays are commonly used in programming to store and manipulate data efficiently.

• Example: ['apple', 'banana', 'orange'] is an array of strings.

Program to find prime numbers in Java

• Take input from user

• Loop through numbers from 2 to input-1

• Check if input is divisible by any number in the loop

• If not, it is a prime number

A pointer in C is a variable that stores the memory address of another variable.

• Pointers are used to manipulate data directly in memory.

• They can be used to pass values by reference to functions.

• Example: int *ptr; ptr = # *ptr = 10; //num now has a value of 10

• Null pointers are used to indicate that a pointer does not point to a valid memory address.

SQL queries are used to retrieve, manipulate and manage data stored in relational databases.

• SELECT statement is used to retrieve data from a table

• UPDATE statement is used to modify data in a table

• DELETE statement is used to delete data from a table

• JOIN statement is used to combine data from multiple tables

• GROUP BY statement is used to group data based on a specific column

• ORDER BY statement is used to sort data based on a specific column

OOPs stands for Object-Oriented Programming. It is a programming paradigm that uses objects to design applications.

• OOPs focuses on creating reusable code and organizing it into objects.

• It uses concepts like inheritance, encapsulation, and polymorphism to achieve this.

• Inheritance allows objects to inherit properties and methods from other objects.

• Encapsulation hides the implementation details of an object from the outside world.

• Polymorphism allows objects to take on multiple f...read more

A column name in a database is a label given to a specific field of data within a table.

• Column names should be descriptive and concise

• Avoid using spaces or special characters in column names

• Use camelCase or snake_case for multi-word column names

• Examples: firstName, dateOfBirth, order_total

Pharmacovigilance is the science and activities related to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems.

• Pharmacovigilance is the process of monitoring and evaluating the safety and efficacy of drugs.

• It involves collecting and analyzing data on adverse drug reactions and other drug-related problems.

• Pharmacovigilance is important for ensuring the safety of patients and improving the quality of healthcare.

• Examples...read more

A list is a collection of items that are ordered and can be accessed by their index.

• Lists are mutable, meaning their contents can be changed.

• Lists can contain elements of different data types.

• Lists are created using square brackets [] and elements are separated by commas.

• Example: my_list = [1, 'apple', True, 3.14]

Reverse a string using Java

• Convert the string to a character array

• Use two pointers, one at the start and one at the end of the array

• Swap the characters at the two pointers and move them towards the center until they meet

• Convert the character array back to a string