Essential Java Interview Topics and Concepts
Java Primitive Types
Java supports eight primitive data types:
8-bit: byte
16-bit: short, char
32-bit: int, float
64-bit: long, double
boolean
Java Data Structures
Arrays
Arrays offer O(1) access time via index, making them excellent for random access operations and sequential iteration. However, their size is fixed at creation time, preventi ...
Posted on Sat, 16 May 2026 08:47:52 +0000 by Someone789
Redis Core Knowledge for Java Backend Interviews
What is Redis
Redis is a high‑performance, in‑memory key‑value database that also supports optional data persistence. It is open‑source and written in C, widely used both as a cache and as a primary datastore for specialised scenarios.
Why Redis Is So Fast
In‑memory storage – data is served directly from RAM, avoiding disk I/O for most operati ...
Posted on Sat, 16 May 2026 00:09:43 +0000 by dave420
Python Interview Questions and Answers
Database and SQL
Query Execution Order
The order of execution for SQL statements:
FROM - identifies the source tables
JOIN - combines rows from multiple tables
ON - specifies join conditions
WHERE - filters rows based on conditions
GROUP BY - groups rows by specified columns
HAVING - filters groups after aggregation
SELECT - selects columns to ...
Posted on Fri, 15 May 2026 01:00:02 +0000 by maxonon
Essential Frontend Interview Questions and Concepts
HTTP Fundamentals
GET vs POST Requests
Characteristic
GET
POST
Idempotency
Yes
No
Usage
Retrieving data
Submitting data
Caching
Cached
Not cached
Parameter Passing
URL query string
Request body
Security
Less secure
More secure
Length Limits
Browser-dependent
No browser limits
Data Types
ASCII only
All types including files
...
Posted on Thu, 14 May 2026 07:59:10 +0000 by brad_fears
JavaScript Interview Challenge: Variable Scope and This Keyword
var value = 1;
function execute()
{
console.log(value);
var value = 2;
console.log(this.value);
this.value = 3;
}
// What will these two statements print to the console?
execute();
var instance = new execute();
Let's analyze this JavaScript interview question step by step.
1. execute() call outputs: *undefined* , *1*
...
Posted on Fri, 08 May 2026 20:03:56 +0000 by bugsuperstar37
HashMap Interview Quick Reference and Best Practices
Core Principles (Three Key Points)
Underlying Structure
HashMap uses an array as the primary storage, combined with linked lists for handling hash collisions, and converts to red-black trees when certain conditions are met. When a linked list exceeds 8 elements and the array length is at least 64, the structure transforms into a red-black tree, ...
Posted on Fri, 08 May 2026 08:50:05 +0000 by dicky18