Java Functional Programming: Lambdas, Streams & Collections

Explore functional programming basics, including functions as first-class objects, pure functions, and higher-order functions, and examine rules like no state, no side effects, immutable variables, and pure recursion over looping.

Explore functional programming in Java 8 using streams and lambda expressions to filter, map to int, and sum without for loops or mutable state.

Explore pure functions in functional programming, which always produce the same output for the same input and have no side effects, with Java examples and guidance on usage.

Explore how functions become first-class objects in functional programming by assigning, passing, and returning functions in Java using lambda expressions and functional interfaces.

Explore higher order functions in Java: functions that take or return other functions, using streams, lambda expressions, and callbacks to write modular, reusable, and testable code.

Explore the four key rules of pure functional programming in Java: no state, no side effects, immutable variables, and recursion over loops, with detailed Java examples.

Explore lambda expressions introduced in Java 8 as anonymous functions you can pass as parameters, enabling functional programming, concise code, and reduced boilerplate through functional interfaces and streams.

Explore lambda expressions in Java by implementing a functional interface with a single abstract method, reducing boilerplate and embracing functional programming through practical examples.

Learn lambda expressions in Java through a calculator example using a functional interface. See how to implement operations like add, subtract, multiply, and divide with lambda syntax and reduced boilerplate.

learn how to pass a lambda expression as a parameter to a method using a functional interface, with drawing and calculator examples that cover addition, subtraction, multiplication, and division.

Discover how to create a thread in java using a lambda expression to implement the runnable interface, a functional interface, reducing boilerplate versus the traditional method.

Discover functional interfaces in Java eight, defined by a single abstract method with optional default and static methods, plus lambda expressions and custom interfaces like predicate, function, supplier, and consumer.

Explore the java.util.function function interface in Java 8, including apply, then, compose, and identity, with lambda-based and anonymous-class examples for data transformation.

Learn how to chain two functions using the andThen method of the Function interface, applying one function to uppercase a string and then another to compute its length.

Explore how to use the Function.compose() method to chain two functions—trim and toUpperCase—via lambdas, applying the first function then the second with their apply methods, and testing the result.

Explain how the static identity method returns the input unchanged, enabling data to pass through without modification via the function interface and apply in Java.

Explore the predicate interface from java.util.function, using lambdas to test booleans for filtering. Understand the test method and key predicates like and, or, negate, and isEqual for condition checks.

Apply the and method of the predicate interface in Java to combine two predicates—not empty strings and strings longer than five characters. Test with 'Hello world' to see true result.

Combine two predicates using the or method in Java, returning true if either predicate is true, demonstrated with less than five and greater than 15 checks via lambdas.

Discover how the negate method reverses a predicate and how isEqual checks input against a target, using tests with an empty string, hello, and Java to illustrate case sensitive equality.

Explore the supplier interface in java 8, a functional interface from java.util.function, implemented with lambdas to supply data, with get returning results, enabling lazy evaluation and default values.

Explore how the supplier interface provides a default configuration when custom configuration is unavailable, using a Java lambda to return a configuration object with url and timeout.

Introduce the consumer interface in Java eight, a java.util.function interface that accepts an input and returns no result, with lambda expressions and andThen for chaining, demonstrated by printing and uppercase.

Explore the BiFunction interface in Java eight, learn its apply and the then method, and implement two-input operations like addition, subtraction, multiplication, and division with lambdas.

Explore how to use the BiFunction interface and the andThen method with a lambda to chain operations in Java, multiplying two numbers and converting the result to a string.

Demonstrate using a BiFunction<Integer, Integer, Integer> to calculate the area of a rectangle via a lambda, simplify the body, call apply with length and width, and print the result.

Explore the BiPredicate interface in Java eight, a two-argument functional interface from java.util.function, and learn its test, and, or, and negate methods with lambda expressions.

Explore how to combine two predicates using the BiPredicate and() method with logical and to require both numbers are positive and even, implemented with lambdas and tested on sample inputs.

Demonstrate the BiPredicate or() method in Java by combining two predicates with the or operator, returning true when at least one condition holds, via positive and even number tests.

Learn how to implement a BiPredicate in Java to compare two strings, negate the predicate to test not equal, and run tests to observe true or false outcomes.