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Function Functional Interface in Java 8 – Definition, Syntax & Real-World Use Cases
The Function functional interface is a predefined interface introduced in Java 8 as part of the java.util.function package. It represents a function that accepts one input argument and produces one result. This interface is widely used in lambda expressions, Stream API operations, and functional programming. A key feature of the Function interface is that it enables developers to define reusable transformation logic, where an input object is converted into another form. For example, converting a String into its length, a Student object into a grade, or an entity into a DTO. Function is functional interface that takes one argument and produces a result , Syntax: Program1 : Write a program…
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Predicate Functional Interface in Java 8 – Definition, Syntax & Real-World Use Cases
Java 8 introduced the concept of functional programming in Java through Lambda Expressions.To support this, Java provides a rich set of predefined functional interfaces . An Interface which contains single abstract method and any number of default and statics method .all predefined functional interface present in java.util.function package. Main Types of Predefined Functional Interfaces 1.Predicate : A predicate is a functional interface that represents a Boolean valued function of one argument . predicate takes one input and return either true or false . the Predicate functional interface is mainly used to represent business conditions or validation rules that return a boolean result and are frequently applied in filtering operations. A…
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Stream API in Java 8: Complete Guide with Examples
Stream api is a powerful abstraction for processing sequence of elements in a functional and declarative style . it allows developers to perform complex data manipulations such as filtering , mapping , sorting and reducing with minimal boilerplate code . Stream represent a pipeline of operations that can be executed either sequentially or in parallel , improving both readability and performance . Purpose of Stream Api The main goals of the stream api are . 1.Simplify data processing: Replace verbose loops with expressive operations 2.Enable Functional programing : use lambda expressions and method references 3. Improve Performance: Support parallel execution with parallel stream . Pipeline in Java Stream A stream…
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Default and Static Methods in Java 8 Interface – Features & Use Cases
A default method is a method define in an interface with a default implementation .it uses the default keyword and allows interfaces to have behavior without forcing all implementing classes to override it . Syntax: The main purpose of default methods is to enable backward combability when evolving interfaces before java8 , adding a new method to an interface would break all implementing classes with default methods, you can add new functionality without affecting existing code . Features of Default Methods in Java Interface with default method Abstract class Use Cases of Default Methods in Java What is Static Method in an Interface A static method in an interface is…
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Functional Programming in Java Using Lambda Expressions
A lambda expression is a short and concise way to represent an anonymous function—a function without a name . Key Features 1.Why Lambda expression required Lambda expression required to enable functional programming ,lambda expression allow you to define small functions without naming them . this is useful when the function is simple and used only once or a few times . Lambda Syntax : 2.Lambda Expression Example Example 1: Addition of Number Without Lambda Expressions With Lambda Expressions Example 2: Find the length of String without Lambda Expressions With Lambda Expression if single statements are there then curly bracket not required , if body contained multiple lines of code then…