Java Full Stack Developer @ Blue Yonder | Spring Boot, Microservices, Kafka, System Design | Breaking down backend systems and Java interviews from the interviewer’s side
1. Why Methods? Imagine printing a line of 30 dashes in 10 different places. Copying the same loop 10 times is tiring, and if you later want 40 dashes, you must change 10 places. A method is a named, reusable block of...
1. What is a program? A computer is extremely fast and extremely obedient, but it has no common sense. It does exactly what it is told, step by step. A program is a list of precise instructions that tells the computer...
1. A program that says more From now on, every example sits inside the frame from Session 1. Here's a program with several output lines: public class Intro { public static void main(String[] args) {...
1. Why variables? So far our programs only print fixed text. Real programs need to remember things: a user's age, a bank balance, a score. A variable is a named storage location in memory (RAM) that holds a value....
1. Arithmetic operators Operator Meaning Example Result + Add 7 + 2 9 - Subtract 7 - 2 5 * Multiply 7 * 2 14 / Divide 7 / 2 3 (not 3.5!) % Remainder (modulus) 7 % 2 1 Integer division: the number-one surprise When both...
1. Widening: automatic and safe Putting a value from a smaller box into a bigger box is always safe, so Java does it automatically. This is called widening (or implicit conversion). Widening happens automatically along...
Why loops ? Print “Rohit“ 5 times? You could copy the 5 times. 1,000 times? A loops runs the same block again and again while a condition stays true. 2. The while loop public class Main { public static void main(String[]...
Recap question: What does Integer.parseInt do, and what happens if the text isn't a number? 1. The if statement Until now every line ran everytime. if runs a block only when the condition is true: import...
🎯 By the end of this session, the candidate can Read text from the keyboard. Convert text input into numbers. Structure a program as input → process → output. Read a crash message and find the problem line. 1. Programs...