10+ Programmer Interview Questions and Answers for Freshers

OOPs is Object Oriented Programming. Java and Python are both OOPs languages, but differ in syntax and usage.

• Java is statically typed, while Python is dynamically typed

• Java requires more verbose syntax, while Python is more concise

• Java is better suited for large-scale enterprise applications, while Python is better for scripting and data analysis

• Java has a stronger emphasis on performance, while Python prioritizes ease of use and readability

• Both languages support inheritance,...read more

Database is crucial for storing and managing data in backend development.

• Database stores and organizes data for efficient retrieval and manipulation.

• It allows for easy querying and filtering of data.

• It enables data consistency and integrity through constraints and validations.

• It facilitates data migration and backup.

• Examples include MySQL, MongoDB, and PostgreSQL.

Java is a compiled language that also uses interpretation at runtime.

• Java code is compiled into bytecode which is then interpreted by the Java Virtual Machine (JVM) at runtime.

• This allows Java to be platform-independent as the bytecode can be executed on any system with a JVM.

• However, some modern JVMs also use just-in-time (JIT) compilation to improve performance.

• JIT compilation compiles bytecode into native machine code at runtime, allowing for faster execution.

• Overall, Java...read more

Use binary search to find the first and last occurrence of the character, then calculate the frequency.

• Use binary search to find the first occurrence of the character in the string.

• Use binary search to find the last occurrence of the character in the string.

• Calculate the frequency by subtracting the indices of the last and first occurrences and adding 1.

OOPs concepts and pillars. Design a Vehicle class based on requirements.

• OOPs concepts: Abstraction, Encapsulation, Inheritance, Polymorphism

• Vehicle class requirements: attributes like make, model, year, methods like start, stop, accelerate

Friend function in C++ is a non-member function that has access to the private and protected members of a class.

• Declared inside the class but defined outside the class scope

• Can access private and protected members of the class

• Can be used to overload operators

• Example: friend void display(A obj) { cout << obj.num; }

• Example: class A { friend void display(A obj); };

Java is a high-level programming language known for its platform independence and object-oriented approach.

• Java is platform-independent, meaning it can run on any operating system

• It is an object-oriented language, focusing on creating reusable code through classes and objects

• Java uses a virtual machine (JVM) to execute code, providing portability and security

• It has a rich set of libraries and frameworks for various purposes, such as JavaFX for GUI development

• Java supports mul...read more

Object-oriented programming concepts focus on classes, objects, inheritance, encapsulation, and polymorphism.

• Classes: Blueprint for creating objects with attributes and methods.

• Objects: Instances of classes that contain data and behavior.

• Inheritance: Ability for a class to inherit attributes and methods from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Polymorphism: Ability for objects of different classes to respond to th...read more

List and dictionary are data structures in programming.

• List is an ordered collection of elements, accessed by index. Example: [1, 2, 3]

• Dictionary is an unordered collection of key-value pairs. Example: {'name': 'John', 'age': 30}

• Lists use square brackets [] while dictionaries use curly braces {}

• Lists can contain duplicate values while dictionaries cannot have duplicate keys

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 overloading and method overriding.

• Example: A shape class can have different subclasses like circle, square, and triangle, each with their own implementation of the draw method.

• Polymorphism makes code more flexible and reusable.

Continue is a keyword in programming that is used to skip the current iteration of a loop and continue with the next iteration.

• Continue is used in loops like for, while, and do-while to skip the current iteration and move to the next one.

• It is often used to skip certain elements in an array or to avoid executing specific code under certain conditions.

• Example: for(int i=0; i<5; i++) { if(i==2) { continue; } System.out.println(i); } This will print 0, 1, 3, 4.

Arrays have fixed size, while lists can dynamically grow. Arrays are faster for random access, while lists are better for insertion/deletion.

• Arrays have a fixed size, while lists can dynamically grow.

• Arrays are faster for random access, while lists are better for insertion/deletion.

• Example: String[] array = new String[5]; List list = new ArrayList<>();

Map is an interface that maps keys to values, while HashSet is a class that implements the Set interface using a hash table.

• Map allows key-value pairs, while HashSet only allows unique elements

• Map can have duplicate values but keys must be unique, HashSet does not allow duplicates

• Map provides key-based access to elements, HashSet does not have a key-value pair structure