Java Lambda Expressions is a feature introduced in Java 8 that allows you to write more concise and expressive code. It is a way to pass a block of code as an argument to a method or constructor. In this blog, we will explore Java Lambda Expressions in detail, including how to declare and use them, and provide example code snippets to illustrate each concept.
Declaring a Java Lambda Expression:
To declare a Java Lambda Expression, you need to use the arrow operator “->”. The left-hand side of the operator specifies the parameters of the lambda expression, and the right-hand side specifies the code to be executed. Here is an example:
(parameter1, parameter2) -> {
// code to be executed
}
In the above example, we declare a lambda expression that takes two parameters and executes the code inside the curly braces.
Using a Java Lambda Expression:
To use a Java Lambda Expression, you need to pass it as an argument to a method or constructor that accepts a functional interface. A functional interface is an interface that contains only one abstract method. Here is an example:
List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5); numbers.stream() .filter(n -> n % 2 == 0) .forEach(System.out::println);
In the above example, we create a list of integers and use a lambda expression to filter even numbers from the list and print them using the forEach() method.
Lambda Expression with a Single Parameter:
If a lambda expression has only one parameter, you can omit the parentheses. Here is an example:
List<String> names = Arrays.asList("Alice", "Bob", "Charlie");
names.forEach(name -> System.out.println(name));
In the above example, we use a lambda expression to print each name in the list.
Lambda Expression with No Parameters:
If a lambda expression has no parameters, you still need to include empty parentheses. Here is an example:
Runnable runnable = () -> {
// code to be executed
};
In the above example, we declare a lambda expression that executes the code inside the curly braces when the Runnable object is run.
Conclusion:
Java Lambda Expressions is a powerful feature that allows you to write more concise and expressive code. In this blog, we explored how to declare and use Java Lambda Expressions, including how to pass them as arguments to methods and constructors, and how to use them with functional interfaces. We also provided example code snippets to illustrate each concept. If you want to write cleaner and more readable code in Java, consider using Java Lambda Expressions.
