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Lambda Expressions in Java

bookLambdas in Stream API

You will often encounter the Stream API when processing collections of data in Java. The Stream API allows you to perform complex data operations in a concise and readable way. Lambda expressions play a central role in this, as they are used to define the behavior of stream operations such as map, filter, and reduce. These operations enable you to transform, filter, and aggregate data declaratively, rather than writing explicit loops and conditionals.

Main.java

Main.java

copy

              
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package com.example;

import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class Main {
    public static void main(String[] args) {
        List<String> names = Arrays.asList("Alice", "Bob", "Charlie", "David", "Eve");
        List<String> upperCaseNamesWithE = names.stream()
            .filter(name -> name.contains("e"))
            .map(name -> name.toUpperCase())
            .collect(Collectors.toList());
        System.out.println(upperCaseNamesWithE);
    }
}

Using lambdas within streams allows you to focus on what you want to do with the data, rather than how to do it. This declarative style improves code readability and maintainability. You express operations like filtering, mapping, and reducing as a sequence of transformations, making your intent clear and your code less error-prone.

Main.java

Main.java

copy

              
123456789101112131415

            
package com.example;

import java.util.Arrays;
import java.util.List;
import java.util.Optional;

public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(10, 23, 5, 99, 34);
        Optional<Integer> max = numbers.stream()
            .max((a, b) -> a.compareTo(b));
        max.ifPresent(m -> System.out.println("Max value: " + m));
    }
}

1. Which of the following Stream API methods commonly use lambda expressions?

2. What is the main difference between the map and filter methods in a Java stream?

question mark

Which of the following Stream API methods commonly use lambda expressions?

Select the correct answer

question mark

What is the main difference between the map and filter methods in a Java stream?

Select the correct answer

Everything was clear?

How can we improve it?

Thanks for your feedback!

SectionΒ 2. ChapterΒ 5

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bookLambdas in Stream API

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You will often encounter the Stream API when processing collections of data in Java. The Stream API allows you to perform complex data operations in a concise and readable way. Lambda expressions play a central role in this, as they are used to define the behavior of stream operations such as map, filter, and reduce. These operations enable you to transform, filter, and aggregate data declaratively, rather than writing explicit loops and conditionals.

Main.java

Main.java

copy

              
1234567891011121314151617

            
package com.example;

import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class Main {
    public static void main(String[] args) {
        List<String> names = Arrays.asList("Alice", "Bob", "Charlie", "David", "Eve");
        List<String> upperCaseNamesWithE = names.stream()
            .filter(name -> name.contains("e"))
            .map(name -> name.toUpperCase())
            .collect(Collectors.toList());
        System.out.println(upperCaseNamesWithE);
    }
}

Using lambdas within streams allows you to focus on what you want to do with the data, rather than how to do it. This declarative style improves code readability and maintainability. You express operations like filtering, mapping, and reducing as a sequence of transformations, making your intent clear and your code less error-prone.

Main.java

Main.java

copy

              
123456789101112131415

            
package com.example;

import java.util.Arrays;
import java.util.List;
import java.util.Optional;

public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(10, 23, 5, 99, 34);
        Optional<Integer> max = numbers.stream()
            .max((a, b) -> a.compareTo(b));
        max.ifPresent(m -> System.out.println("Max value: " + m));
    }
}

1. Which of the following Stream API methods commonly use lambda expressions?

2. What is the main difference between the map and filter methods in a Java stream?

question mark

Which of the following Stream API methods commonly use lambda expressions?

Select the correct answer

question mark

What is the main difference between the map and filter methods in a Java stream?

Select the correct answer

Everything was clear?

How can we improve it?

Thanks for your feedback!

SectionΒ 2. ChapterΒ 5
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