Vincent Vauban’s Post

Text Block simple example In this post under Java Core, I will introduce you to newly added "Text Block" feature. This feature was added as part of Java 15. Pre Java 15, if we have to declare a multiline string we used to declare it as shown below String result = "Since Java 15, text blocks are \n" + "available as a standard feature.\n" + "With Java 13 and 14, \n" + "we needed to enable it as a preview feature.";...

✅ Java Features – Step 18: Text Blocks (Java 15) 🧾 Before Java 15, writing multi-line strings required lots of concatenation. Example: String query = "SELECT * FROM users\n" + "WHERE age > 25\n" + "ORDER BY name"; Java 15 introduced Text Blocks, which allow clean multi-line strings. String query = """ SELECT * FROM users WHERE age > 25 ORDER BY name """; Why this matters Cleaner multi-line strings Great for SQL queries, JSON, HTML, and XML Less escaping and string concatenation Much more readable code Example with JSON String json = """ { "name": "Mariya", "role": "Developer" } """; Key takeaway Text blocks make working with structured text much easier and improve code readability. Next up: Java Records (Java 16) 🚀

Day 11 - What I Learned In a Day(JAVA) Today I learned that Java variables are classified into two areas and understood their scope. 1️⃣ Global Area (Instance Variable) Declared inside the class but outside methods. Accessible by all methods inside the class. Scope: Entire class. Memory is created when the object is created. 2️⃣ Local Area (Local Variable) Declared inside a method, constructor, or block. Accessible only inside that method or block. Scope: Limited to that block only. Memory is created when the method runs. Types of Variables in Java (Based on Scope): 1️⃣ Local Variable Declared inside a method. Used only inside that method. Cannot be used outside the method. 2️⃣ Non-Static Variable (Instance Variable) Declared inside the class but outside methods. Belongs to the object. Each object has its own copy. 3️⃣Static Variable Declared using static keyword. Belongs to the class. One copy is shared by all objects. Three Important Statements in Java (Variables): 1️⃣ Declaration Creating a variable. You are telling Java the type and name of the variable. No value is given. Example: int a; 2️⃣ Initialization Giving a value to a variable. The variable must already be declared. Example: a = 10; 3️⃣ Declaration + Initialization Creating the variable and giving value at the same time. Example: int a = 10; Practiced 👇 #Java #Variables #Programming #CodingJourney

✅ Java Features – Step 21: Pattern Matching for instanceof (Java 17) ⚡ Before Java 17, using instanceof required an extra cast. Example (old style): if (obj instanceof String) { String s = (String) obj; System.out.println(s.length()); } Java 17 simplifies this with pattern matching. if (obj instanceof String s) { System.out.println(s.length()); } Now the variable s is automatically created after the type check. Why this matters Less boilerplate code Safer type checking Improved readability Fewer casting mistakes Example Object value = "Java"; if (value instanceof String str) { System.out.println(str.toUpperCase()); } Key takeaway Pattern matching reduces repetitive casting and makes type-checking logic cleaner. This is part of Java’s effort to modernize the language. Next up: Recap – Key Features from Java 8 → Java 17 🚀

📄 On paper this looks like a small syntax tweak, ✨ but in real projects it feels like a relief. 🔧 DTO mapping, 📝 logging, or ⚙️ handling different event types in a backend system — we used to write instanceof checks followed by repetitive casts everywhere. ❌ It wasn’t just ugly, it was error‑prone. ✅ Now the flow is natural: if (event instanceof PaymentEvent pe) { auditLogger.log(pe.getTransactionId()); } 💡 This isn’t just saving a line of code. 👉 It’s about intent. 👥 When a teammate reads this, they immediately see what’s happening without being distracted by boilerplate. 🚀 In practice, these “small” changes: 🔓 reduce friction 👶 make onboarding easier for juniors 🎯 help teams focus on business logic instead of ceremony 📌 My takeaway: Code is not only for machines to run, but for humans to read, share, and maintain. Readability = productivity. This way your repost feels more personal, visually appealing, and relatable to everyday coding practice.

✅ Java Features – Step 22: Java 8 → Java 17 Recap 🚀 Over the past few posts, I’ve been revisiting some key Java features introduced from Java 8 to Java 17. A quick recap of the highlights: 🔹 Java 8 Streams API Optional Functional Interfaces Lambda Expressions 🔹 Java 9–11 Factory methods (List.of, Set.of, Map.of) var for local variable type inference New String methods (isBlank, strip, repeat) Modern HttpClient API 🔹 Java 14–15 Switch expressions Text blocks 🔹 Java 16–17 Records Sealed classes Pattern matching for instanceof Key takeaway Java has evolved significantly to: Reduce boilerplate Improve readability Support modern programming patterns Understanding these features helps write cleaner and more maintainable backend code. Next up: Practical examples of modern Java features in real backend applications ⚙️

Something new I learned about Java Strings Why does this print true? 👉 String a = "Peter"; String b = "Peter"; System.out.println(a == b); Because of the String Constant Pool. Java stores string literals in a special memory area. If the value already exists, it reuses the same reference. Now look at this: 👉 String a = new String("Peter"); String b = new String("Peter"); Now a == b is false. Why? Using new forces Java to create a new object in heap memory, even if the same value exists in the pool. Why does Java do this? To optimize memory usage. Since Strings are immutable, Java can safely reuse the same object for identical literals. 💡 Key takeaway: == compares references .equals() compares actual content #Java #JavaDeveloper #BackendDevelopment #SpringBoot #SoftwareEngineering #LearningInPublic

🔥 String vs StringBuilder in Java In Java, String is immutable and StringBuilder is mutable — and that makes a big difference in performance. 🔹 String • Immutable (cannot be changed after creation) • Every modification creates a new object in memory • Slower when used inside loops • Thread-safe ⚠️ Repeated concatenation (like in loops) leads to unnecessary object creation and memory usage. 🔹 StringBuilder • Mutable (modifies the same object) • No new object created for each change • Faster and memory efficient • Not thread-safe 🚀 Best choice for frequent string modifications, especially inside loops. 🎯 When to Use? ✅ Use String → When value doesn’t change ✅ Use StringBuilder → When performing multiple concatenations 💡 In backend applications, choosing StringBuilder for heavy string operations improves performance significantly. #Java #BackendDevelopment #JavaProgramming #Performance

🚀 Java Method Arguments: Pass by Value vs Pass by Reference Ever wondered why Java behaves differently when passing primitives vs objects to methods? 🤔 This infographic breaks it down clearly: ✅ Pass by Value – When you pass a primitive, Java sends a copy of the value. The original variable stays unchanged. ✅ Objects in Java (Copy of Reference) – When you pass an object, Java sends a copy of the reference. You can modify the object’s data, but the reference itself cannot point to a new object. 💡 Why it matters: Prevent bugs when modifying data inside methods Understand how Java handles variables and objects under the hood 🔥 Fun Fact: Even objects are passed by value of reference! Java is always pass by value – whether it’s a primitive or an object. #Java #Programming #CodingTips #JavaDeveloper #SoftwareEngineering #LinkedInLearning #CodeBetter

🚀 Java 8 Complete Feature List – Day 1 of My Java 8 Series Java 8 (released in 2014) was one of the biggest upgrades in Java history. It didn’t just add features. It changed the way we write Java. With Java 8, Java officially stepped into functional programming, cleaner code, and powerful data processing. Here’s a complete list of important Java 8 features 👇 1️⃣ Lambda Expressions → Write shorter, cleaner code → Replace anonymous inner classes 2️⃣ Functional Interfaces → Single abstract method → Predicate → Function → Consumer → Supplier → UnaryOperator → BinaryOperator 3️⃣ Method References (::) → Static method reference → Instance method reference → Constructor reference 4️⃣ Stream API 🔥 → filter() → map() → reduce() → collect() → Parallel Streams 5️⃣ Default Methods in Interfaces → Method implementation inside interfaces → Backward compatibility 6️⃣ Static Methods in Interfaces 7️⃣ Optional Class → Better null handling → Avoid NullPointerException 8️⃣ New Date & Time API (java.time) → LocalDate → LocalTime → LocalDateTime → ZonedDateTime → Period & Duration 9️⃣ CompletableFuture → Asynchronous programming → Non-blocking operations 🔟 Nashorn JavaScript Engine 1️⃣1️⃣ Base64 Encoding & Decoding 1️⃣2️⃣ Repeatable & Type Annotations 1️⃣3️⃣ Collection API Enhancements → forEach() → removeIf() → replaceAll() → computeIfAbsent() → merge() 1️⃣4️⃣ Arrays.parallelSort() 1️⃣5️⃣ Concurrency Enhancements → Fork/Join improvements → StampedLock 📌 Over the next few days, I’ll break down each feature with: Real-world examples Interview-focused explanations Practical use cases If you're preparing for interviews or want to write cleaner Java code, this series will help. Follow along 🚀 #Java #Java8 #BackendDevelopment #SoftwareEngineering #Coding #InterviewPreparation #SpringBoot