Lovepreet S (Java Experts) ☁️

★ Sr Backend Developer | 9+ years Experience
★ Sharing my experience via tweets & threads
★ Explains complex concepts

[Lovepreet S (Java Experts) ☁️ @java_experts]

A Roadmap to become JAVA backend developer.

🧵👇

[Lovepreet S (Java Experts) ☁️ @java_experts]

In Action
Integer num1 = 50;
Integer num2 = 50;
System.out.println(num1 == num2); // true (pooled!)

Integer num3 = 150;
Integer num4 = 150;
System.out.println(num3 == num4); // false (not pooled!)

[Lovepreet S (Java Experts) ☁️ @java_experts]

Try this 🤔
Integer a = 100; Integer b = 100;
System.out.println( a == b) // true

Integer x = 200; Integer y = 200; // false

you know why?! #Java #Programming 👇

[Lovepreet S (Java Experts) ☁️ @java_experts]

The Tricky Part: == vs .equals()
This is where == gets tricky! == checks if two references point to the exact same object. For numbers in the pool, they often do. Outside the pool, even if values are identical, they're separate objects. Always use .equals() for value comparison

[Lovepreet S (Java Experts) ☁️ @java_experts]

Key Takeaways:
Java's String Pool reuses literals.
new String() always creates new objects.
intern() forces pooling.
== vs .equals() is crucial for comparison

[Lovepreet S (Java Experts) ☁️ @java_experts]

Ever wonder why "hello" == "hello" is true, but new String("hello") == new String("hello") is false? Let's unravel this 👇
The String Pool

[Lovepreet S (Java Experts) ☁️ @java_experts]

Classic Gotcha: `==` vs `.equals()`
Comparing user input (often dynamically created Strings) with constant literals using == will likely fail! ❌ Always use .equals() for content comparison. Remember: == for reference, .equals() for value.

[Lovepreet S (Java Experts) ☁️ @java_experts]

Q: How do you share variable in thread life cycle?

A: Java ThreadLocal class allows the storage of data that is specific to each thread separately.
It is often used to implement thread-specific context or to avoid synchronisation for thread-local data

[Lovepreet S (Java Experts) ☁️ @java_experts]

@vikasrajputin @DThompsonDev This is great advice.

[Lovepreet S (Java Experts) ☁️ @java_experts]

@dolapo_47 Lets break the threads together

[Lovepreet S (Java Experts) ☁️ @java_experts]

What do you think most difficult/complex topic in JAVA ?

[Lovepreet S (Java Experts) ☁️ @java_experts]

@vvicazz Most common answer 😀

[Lovepreet S (Java Experts) ☁️ @java_experts]

@Shubh28659122 True, Threads are a bit complicated, but if you understand the concept, they're a lot of fun.

[Lovepreet S (Java Experts) ☁️ @java_experts]

@AmosSohan True, Threads are tricky, Dp is really a thing

[Lovepreet S (Java Experts) ☁️ @java_experts]

@VirtualCoder20 haha !! Thread are little bit tricky