Veolia Water Technologies Field Engineer Interview Questions and Answers

C++ is an extension of C with object-oriented programming features.

• C++ supports classes and objects while C does not.

• C++ has better support for polymorphism and inheritance.

• C++ has a standard template library (STL) while C does not.

• C++ allows function overloading while C does not.

• C++ has exception handling while C does not.

OOPs stands for Object-Oriented Programming. It is a programming paradigm based on the concept of objects.

• OOPs focuses on creating objects that contain both data and functions to manipulate that data.

• It emphasizes on encapsulation, inheritance, and polymorphism.

• Examples of OOPs languages are Java, C++, Python, etc.

Polymorphism is the ability of an object to take on many forms.

• It allows objects of different classes to be treated as if they were objects of the same class.

• It is achieved through method overriding and method overloading.

• Example: A shape class can have different subclasses like circle, square, triangle, etc. and all of them can be treated as shapes.

• Example: A method can have different implementations in different clas...read more

Data abstraction is the process of hiding implementation details and showing only the necessary information to the user.

• It is a way of organizing complex systems

• It allows users to interact with complex systems without needing to understand the underlying details

• It helps to reduce complexity and increase efficiency

• Examples include object-oriented programming and APIs

A C program to reverse a given string.

• Declare a character array to store the input string.

• Use a loop to iterate through the string and swap the characters.

• Print the reversed string.

Swapping two numbers using macro in C language

• Use a temporary variable to store the value of one number

• Assign the value of the second number to the first number

• Assign the value of the temporary variable to the second number

• Define a macro for swapping the numbers

• Example: #define SWAP(a,b) {int temp; temp=a; a=b; b=temp;}

NACL and security groups are both AWS network security features, but NACL operates at the subnet level while security groups operate at the instance level.

• NACL is stateless while security groups are stateful

• NACL can allow or deny traffic based on IP addresses, protocols, and ports while security groups only allow traffic

• NACL rules are evaluated in order while security group rules are evaluated independently

• NACL can be ...read more

Public and private subnets can be identified based on their IP address range and their accessibility from the internet.

• Public subnets have IP addresses that are accessible from the internet.

• Private subnets have IP addresses that are not accessible from the internet.

• Public subnets are typically used for resources that need to be accessed from the internet, such as web servers.

• Private subnets are typically used for resou...read more

S3 is for frequently accessed data while Glacier is for long-term archival storage.

• S3 is designed for frequently accessed data while Glacier is for long-term archival storage.

• S3 has low latency retrieval times while Glacier has higher retrieval times.

• S3 is more expensive than Glacier for storage and retrieval.

• Glacier has a tiered pricing model based on retrieval times and storage duration.

• S3 is suitable for storing dat...read more

AMI is a virtual machine while S3 is a storage service in AWS.

• AMI stands for Amazon Machine Image and is a pre-configured virtual machine that can be used to create EC2 instances.

• S3 stands for Simple Storage Service and is a scalable object storage service that can be used to store and retrieve data.

• AMI is used to create EC2 instances while S3 is used to store and retrieve data.

• AMI is used for computing while S3 is use...read more

The parameter for creating group policy using JSON is a JSON object containing the policy settings.

• The JSON object should include the policy name, description, and settings.

• The settings can include values for registry keys, security options, and other policy settings.

• Example: {"policyName": "Password Policy", "description": "Enforces password complexity requirements", "settings": {"MinimumPasswordLength": 8, "PasswordC

Virtual DOM is a lightweight copy of the actual DOM used for efficient updates.

• Virtual DOM is a concept used in modern web development frameworks like React.

• It is a lightweight copy of the actual DOM that is used to track changes and update the actual DOM efficiently.

• When a change is made to the virtual DOM, it is compared to the previous version to determine the minimum number of changes required to update the actual ...read more