Basics Writer A Stream in Java is a new abstraction introduced in Java 8. It represents a sequence of elements (like a collection) that can be processed in a functional way. But unlike collections: It doesn’t store data. It operates on data from a source, such as a collection, an array, or I/O channels. It is immutable—you … Read more
Java 8 provides several ready-to-use functional interfaces in the java.util.function package. These interfaces make it easy to write cleaner and reusable code. Let’s start with one of the most commonly used: Predicate<T> A Predicate is a functional interface that represents a single argument function that returns a boolean result. It is commonly used for evaluating … Read more
A functional interface in Java is a special type of interface that has only one abstract method, meaning there is only one method to implement. It can also have default or static methods, but only one method must be abstract. Java 8 also introduced a new annotation called @FunctionalInterface that you can use to mark your … Read more
Java 8 introduced several powerful features, and one of the most important among them is Lambda Expressions. If you’re new to programming or coming from older Java versions, lambda expressions might seem strange at first, but they make your code shorter, cleaner, and easier to understand. What is a Lambda Expression? A lambda expression is … Read more
A String is a sequence of characters like “Hello” or “123”. In Java, String is a class, not a primitive type, and it’s used to store text. 1. What is the String Pool in Java? The String Pool is a special area in memory where Java stores unique string literals. If you create two strings … Read more
A Hashtable in Java is a data structure that stores data in key-value pairs. It’s like a dictionary you use a key to find a value. Example: hashtable.put(“name”, “John”); Now you can get the value “John” by using the key “name”. Now, Why No Null Keys or Values? Java’s Hashtable does not allow null as … Read more
Before you can cook a meal, you need a kitchen with the right tools like a stove, a pot, and ingredients. Similarly, before you can write and run Java programs, you need to set up your Java development environment a few tools that help you write, check, and run your Java code. What Do You … Read more
Imagine you wrote a letter and made copies of it. Now you want people to read it but they all speak different languages. You’d need a translator for each one, right? Java works in a similar way! You write your code once, and Java takes care of the translation for each type of computer or … Read more
Java is a high-level, object-oriented, and general-purpose programming language used to build a wide range of applications from mobile apps and websites to games and enterprise software. It was created in 1995 by Sun Microsystems (now owned by Oracle). Java is known for being simple, secure, and fast — and most importantly, for working on … Read more
Let’s Start with a Simple Question: Have you ever given instructions to someone? Like: “Turn off the lights.” “Please bring me a glass of water.” “Open the door.” When you do that, you’re communicating with another person to make something happen. In the same way, a programming language is a special language we use to … Read more