200+ Developer Interview Questions and Answers

I regularly use Python in my work.

• Python is a versatile and powerful programming language.

• It is widely used for web development, data analysis, and automation.

• Python has a large and active community, making it easy to find support and resources.

• Some popular Python frameworks and libraries include Django, Flask, and NumPy.

Find element in 2D array which is max in column and min in row with minimum comparisons

• Iterate over rows and columns to find max and min elements respectively

• Compare the max element of a column with the min element of its row

• Return the element if it satisfies the condition

• Consider edge cases like multiple elements satisfying the condition

To ensure accurate estimates for a project, I follow these steps:

• Thoroughly analyze project requirements and scope

• Break down the project into smaller tasks

• Consider past project data and historical performance

• Consult with team members and stakeholders

• Use estimation techniques like bottom-up or top-down

• Factor in potential risks and uncertainties

• Regularly review and update estimates as the project progresses

Write a formula to display A if A is present, display B if B is present else display None.

• Use conditional statements to check if A or B is present

• If A is present, display A

• If B is present, display B

• If neither A nor B is present, display None

No, the 'this' keyword cannot be equal to null.

• The 'this' keyword refers to the current instance of a class.

• It is used to access the members of the current object.

• Since 'this' refers to an object, it cannot be null.

To handle a team, identify areas of improvement for each team member and get approval from the Director.

• Regularly communicate with team members to understand their strengths and weaknesses.

• Provide constructive feedback and coaching to help team members improve.

• Set clear goals and expectations for each team member.

• Encourage collaboration and teamwork within the team.

• Get approval from the Director before implementing any major changes or improvements.

C++ is a compiled language while Java is an interpreted language. Both have their own advantages and disadvantages.

• C++ is faster and more efficient than Java due to its compiled nature.

• Java is more platform-independent and has better memory management.

• C++ is commonly used for system-level programming while Java is used for web and mobile applications.

• Choosing between the two depends on the specific project requirements and goals.

Explanation of Java class loading and dynamic class loading.

• Java class loaders are responsible for loading classes into the JVM.

• There are three types of class loaders: bootstrap, extension, and application.

• To run a class in a package, you need to specify the fully qualified name of the class.

• Dynamic class loading allows classes to be loaded at runtime instead of compile time.

• This can be useful for plugins or modules that are not known at compile time.

Fill the 3 gallon jug, pour it into the 5 gallon jug, fill the 3 gallon jug again, pour it into the 5 gallon jug until it is full, leaving 1 gallon in the 3 gallon jug.

• Fill the 3 gallon jug

• Pour the 3 gallon jug into the 5 gallon jug

• Fill the 3 gallon jug again

• Pour the 3 gallon jug into the 5 gallon jug until it is full

• The 4 gallon jug will have 1 gallon of water

Constructor overriding is not allowed in Java to maintain the integrity of the object creation process.

• Constructor is used to initialize the object state, and allowing overriding can lead to unexpected behavior.

• Inheritance allows the subclass to inherit the superclass constructor, but not override it.

• If a subclass needs to modify the behavior of the superclass constructor, it can use constructor chaining or call a separate method.

• Example: If a subclass overrides the superclas...read more

I know multiple programming languages.

• I am proficient in Java, Python, and C++.

• I have experience with web development languages such as HTML, CSS, and JavaScript.

• I am familiar with scripting languages like Ruby and Perl.

• I have worked with database query languages like SQL.

• I am constantly learning and exploring new programming languages.

Query to find the second highest salary in a table.

• Use the MAX() function to find the highest salary.

• Use the WHERE clause to exclude the highest salary from the result.

• Use the MAX() function again to find the second highest salary.

Create a function to extract the first word from a sentence and modify the sentence to exclude that word.

• Define a function that takes a string as input.

• Use string methods to split the sentence into words.

• Return the first word and modify the original string to exclude it.

• Example: For input 'Hello World', return 'Hello' and modify to 'World'.

• Handle edge cases like empty strings or single-word inputs.

Normalization is used to eliminate data redundancy and improve data integrity. 3NF ensures that each attribute is dependent on the primary key.

• Normalization helps in organizing data in a structured manner

• It eliminates data redundancy and inconsistencies

• 3NF ensures that each attribute is dependent on the primary key

• For example, a table with columns like Order ID, Product ID, and Customer ID can be normalized to eliminate redundant data

Demonstrating the execution of three sequential programs in a coding interview.

• Understand the requirements of each program before coding.

• Write clean and efficient code for each program.

• Test each program individually to ensure correctness.

• Use comments to explain complex logic in the code.

• Example: For a program that calculates the sum of an array, ensure to handle edge cases.

Subsequences are derived from a sequence by deleting some elements without changing the order of the remaining elements.

• A subsequence can be formed by deleting zero or more elements. Example: From 'abc', subsequences include '', 'a', 'b', 'c', 'ab', 'ac', 'bc', 'abc'.

• The number of subsequences of a string of length n is 2^n. For 'abc' (n=3), there are 2^3 = 8 subsequences.

• Subsequences differ from substrings; substrings require contiguous elements. Example: 'abc' has substring...read more

Connect nodes to their right in a binary tree using an extra pointer.

• Traverse the tree using level order traversal

• For each node, connect its right child to the next node in the level

• If there is no next node, set the right child to null

Inheritance is a mechanism in OOP where a new class is derived from an existing class. Overloading is having multiple methods with the same name but different parameters. Overriding is having a method in the subclass with the same name and parameters as in the superclass.

• Inheritance allows for code reuse and promotes code organization.

• Overloading is used to have multiple methods with the same name but different parameters.

• Overriding is used to change the implementation of a m...read more

No, static and public cannot be interchanged.

• Static and public are two different keywords in programming.

• Static is used to define a variable or method that belongs to the class itself, rather than an instance of the class.

• Public is an access modifier that allows the variable or method to be accessed from anywhere in the program.

• Interchanging static and public would result in a syntax error.

• For example, in Java, the following code is valid: public static int myVariable = 10;

• Bu...read more

Managing computing priorities involves prioritizing requests based on urgency, importance, and available resources.

• Assess the urgency and importance of each request

• Consider the impact on business goals and objectives

• Evaluate the available resources and capacity

• Communicate with stakeholders to understand their needs

• Establish a prioritization framework or criteria

• Regularly review and adjust priorities as needed

Getters and setters enhance encapsulation, allowing controlled access to object properties while providing security and validation.

• Encapsulation: Getters and setters encapsulate the internal state of an object, preventing direct access to properties.

• Validation: They allow for validation of data before it is set, ensuring that only valid data is stored. Example: setting age must be a positive number.

• Security: By restricting direct access, they protect sensitive data from unint...read more

Virtual functions allow polymorphism in C++. Vtable is a lookup table for virtual functions and vpointer points to it.

• Virtual functions are used to achieve runtime polymorphism

• Vtable is a table of function pointers for virtual functions

• Vpointer points to the vtable of the object

• When a virtual function is called, the vpointer is used to lookup the correct function in the vtable

• Vtable is created at compile time and is unique for each class

The most popular SDLC model is Agile.

• Agile is iterative and flexible, allowing for changes throughout the development process.

• It emphasizes collaboration and customer satisfaction.

• Other popular models include Waterfall, Spiral, and V-Model.

• Agile is commonly used in software development, but can be applied to other industries as well.

Yes, we can handle exceptions in constructor and destructor.

• In constructor, we can use try-catch block to handle exceptions.

• In destructor, we should avoid throwing exceptions as it can lead to undefined behavior.

• If an exception is thrown in constructor, the object is not fully constructed and should be destroyed.

• If an exception is thrown in destructor, it should be caught and handled properly to avoid program termination.

useMemo is used to memoize a value while useCallback is used to memoize a function.

• useMemo is used to optimize expensive computations by caching the result and returning it if the inputs are the same.

• useCallback is used to optimize expensive function creation by caching the function and returning it if the inputs are the same.

• useMemo returns a value while useCallback returns a memoized function.

• useMemo is used for memoizing values that are not functions while useCallback is u...read more

To setup a network in a lab, you need equipment and a plan.

• Determine the network topology and design

• Choose appropriate networking equipment such as routers, switches, and cables

• Configure network settings such as IP addresses and subnet masks

• Test the network to ensure connectivity and functionality

• Consider security measures such as firewalls and access control

• Examples of equipment: Cisco routers, Juniper switches, Cat6 Ethernet cables

Types of Constructors

• Default constructor: No arguments, initializes object with default values

• Parameterized constructor: Takes arguments and initializes object with provided values

• Copy constructor: Creates a new object by copying the values of an existing object

• Static constructor: Initializes static members of a class

• Private constructor: Restricts the creation of objects from outside the class