Junior Backend Developer
Junior Backend Developer Interview Questions and Answers
Q1. 4. Basic Difference between Trees and Graph and the way we can traverse them
Trees are a type of graph with a hierarchical structure. Graphs are a collection of nodes and edges.
Trees have a single root node, while graphs can have multiple disconnected nodes.
Traversal of trees can be done using depth-first or breadth-first search algorithms.
Traversal of graphs can be done using various algorithms like Dijkstra's algorithm, Bellman-Ford algorithm, etc.
Q2. What is update query in SQL to update data?
The UPDATE query is used to modify existing data in a database table.
The UPDATE query is followed by the name of the table and the SET keyword to specify the columns to be updated.
The WHERE clause is used to specify the condition for updating specific rows.
Multiple columns can be updated in a single UPDATE query.
The UPDATE query can be used with various operators like =, +, -, *, /, etc.
Example: UPDATE employees SET salary = 50000 WHERE department = 'IT';
Q3. 2. Convert a Binary Tree into an inverted Binary Tree
Invert a given binary tree by swapping left and right child nodes recursively.
Recursively swap left and right child nodes of each node in the binary tree.
Start from the root node and swap its left and right child nodes.
Then, recursively swap the left and right child nodes of the left and right child nodes of the root node.
Repeat the process until all nodes have been swapped.
Return the inverted binary tree.
Q4. How to kill a process in linux?
Use the 'kill' command followed by the process ID to terminate a process in Linux.
Use 'ps' command to find the process ID of the process you want to kill
Use 'kill' command followed by the process ID to terminate the process
You can also use 'kill -9' followed by the process ID for a forceful termination
Q5. What is PATCH method in HTTP?
PATCH method in HTTP is used to partially update a resource on the server.
PATCH requests are used to make partial updates to a resource
It is typically used when you want to update only a few fields of an existing resource
The PATCH request body contains the changes to be applied to the resource
Q6. What is teh structure of JWT?
JWT (JSON Web Token) is a compact, URL-safe means of representing claims to be transferred between two parties.
JWT consists of three parts: header, payload, and signature.
Header typically consists of the type of token and the signing algorithm being used.
Payload contains the claims. Claims are statements about an entity (typically the user) and additional data.
Signature is created by encoding the header, payload, a secret, and the algorithm specified in the header.
JWTs are ty...read more
Share interview questions and help millions of jobseekers 🌟
Q7. different between linkdlist and aarylist
LinkedList is a data structure where each element points to the next element, while ArrayList is a resizable array implementation.
LinkedList uses pointers to connect elements, while ArrayList uses an underlying array to store elements.
LinkedList allows for efficient insertion and deletion of elements, while ArrayList is more efficient for random access.
LinkedList is not contiguous in memory, while ArrayList is contiguous in memory.
Example: LinkedList: 1 -> 2 -> 3 -> 4, ArrayL...read more
Q8. Why do we use CORS?
CORS is used to allow or restrict cross-origin requests in web applications.
CORS is used to prevent malicious websites from making unauthorized requests to a different origin.
It allows servers to specify who can access their resources by setting appropriate headers.
CORS is important for security and privacy reasons in web development.
Example: If a frontend application on domain A wants to make a request to a backend API on domain B, CORS must be implemented to allow this comm...read more
Junior Backend Developer Jobs
Q9. any program of recursion
Recursion is a programming technique where a function calls itself in order to solve a problem.
Recursion involves breaking down a problem into smaller subproblems and calling the function recursively on each subproblem.
Base case is important in recursion to prevent infinite loop.
Examples of recursive functions include factorial calculation, Fibonacci sequence generation, and tree traversal.
Q10. write code for shorting
Code for sorting an array of strings
Use a sorting algorithm like bubble sort, selection sort, or quicksort
Implement the sorting algorithm in a function that takes an array of strings as input
Return the sorted array of strings
Interview Questions of Similar Designations
Interview experiences of popular companies
Calculate your in-hand salary
Confused about how your in-hand salary is calculated? Enter your annual salary (CTC) and get your in-hand salary
Reviews
Interviews
Salaries
Users/Month