Course Content

Java Data Structures

1. Fundamental Data Structures in Java

Introduction to Data Structures List and ArrayList in Java Challenge: Library Management System CRUD Operations in Java LinkedList in Java Implementing LinkedList in Java Challenge: Implementing size and delete Methods in LinkedList Quiz: Fundamental Data Structures

2. Advanced Data Structures in Java

Queue Data Structure in Java Deque Data Structure in Java Challenge: Implementing a TaskManager Service Stack Data Structure in Java Challenge: Implementing BrowserHistory Quiz: Advanced Data Structures

3. Mastering Map in Java

What is Map?Working with HashMap in Java HashMap Practice in Java Map with Other Data Structures Quiz: Mastering Map

4. Advanced Java Features and Techniques

Working with Enum in Java Challenge: Implementing Character Classes Stream API in Java Method Reference in Java Practicing with Stream API Quiz: Enum and Stream API

Practicing with Stream API

It's time for you to practice with Stream API. You have a few straightforward tasks involving the use of various Stream API methods. This time, no specific tasks will be provided. Instead, I'll give you a list to work with and what the expected result should be. In other words, your goal is to perform operations on the list to achieve the expected outcome.

This type of task can help you develop the skill of achieving results without a clear specification. You'll only see the input data and the expected result.

You need to use Stream API to accomplish these tasks!

Task 1:

Input:

Main


              1234567891011
            
package com.example;

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

public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
        // Write your code here
    }
}

Use Stream API to square each number in the list and collect the result into a new list. Expected Output:


java

Use map() and toList() methods here.


java

Task 2:

Input:

Main


              1234567891011
            
package com.example;

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

public class Main {
    public static void main(String[] args) {
        List<String> names = Arrays.asList("Alice", "Bob", "Charlie", "David", "Eva");
        // Write your code here
    }
}

Use Stream API to find the length of the longest name in the list. Expected Output:


java

Use map() and max() intermediate methods, and the get() terminal method.


java

Task 3

Input:

Main


              123456789101112131415
            
package com.example;

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

public class Main {
    public static void main(String[] args) {
        List<String> sentences = Arrays.asList(
                "Java Stream API provides a fluent interface for processing sequences of elements.",
                "It supports functional-style operations on streams of elements, such as map-reduce transformations.",
                "In this exercise, you need to count the total number of words in all sentences."
        );
        // Write your code here
    }
}

Use Stream API to count the total number of distinct words (case-insensitive) in all the sentences. Expected Output:


java

Use flatMap() and distinct() intermediate methods, and the count() terminal method.


java

Task 4:

Input:

Main


              1234567891011
            
package com.example;

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

public class Main {
    public static void main(String[] args) {
        List<String> words = Arrays.asList("apple", "banana", "cherry", "date", "elderberry");
        // Write your code here
    }
}

Use Stream API to find the concatenation of the first two words that have even lengths.

Expected Output:


java

Use filter() and limit() intermediate methods, and the collect() terminal method.


java

Task 5:

Input:

Main


              1234567891011
            
package com.example;

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

public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
        // Write your code here
    }
}

Use Stream API to find the sum of the squares of even numbers in the list.

Expected Output:


java

Use mapToInt() and filter() intermediate methods, and the sum() terminal method.


java

Good job!

If you've completed all the tasks, well done!

Some methods in the tasks may not have been covered earlier. To explore them, open IntelliJ IDEA and check their functionality.

Programming is about continuous learning, so explore new solutions, search online, and refer to documentation when needed.

Everything was clear?

Thanks for your feedback!

Section 4. Chapter 5

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Course Content

Java Data Structures

1. Fundamental Data Structures in Java

2. Advanced Data Structures in Java

3. Mastering Map in Java

What is Map?Working with HashMap in Java HashMap Practice in Java Map with Other Data Structures Quiz: Mastering Map

4. Advanced Java Features and Techniques

Working with Enum in Java Challenge: Implementing Character Classes Stream API in Java Method Reference in Java Practicing with Stream API Quiz: Enum and Stream API

Practicing with Stream API

This type of task can help you develop the skill of achieving results without a clear specification. You'll only see the input data and the expected result.

You need to use Stream API to accomplish these tasks!

Task 1:

Input:

Main


              1234567891011
            
package com.example;

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

public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
        // Write your code here
    }
}

Use Stream API to square each number in the list and collect the result into a new list. Expected Output:


java

Use map() and toList() methods here.


java

Task 2:

Input:

Main


              1234567891011
            
package com.example;

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

public class Main {
    public static void main(String[] args) {
        List<String> names = Arrays.asList("Alice", "Bob", "Charlie", "David", "Eva");
        // Write your code here
    }
}

Use Stream API to find the length of the longest name in the list. Expected Output:


java

Use map() and max() intermediate methods, and the get() terminal method.


java

Task 3

Input:

Main


              123456789101112131415
            
package com.example;

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

public class Main {
    public static void main(String[] args) {
        List<String> sentences = Arrays.asList(
                "Java Stream API provides a fluent interface for processing sequences of elements.",
                "It supports functional-style operations on streams of elements, such as map-reduce transformations.",
                "In this exercise, you need to count the total number of words in all sentences."
        );
        // Write your code here
    }
}

Use Stream API to count the total number of distinct words (case-insensitive) in all the sentences. Expected Output:


java

Use flatMap() and distinct() intermediate methods, and the count() terminal method.


java

Task 4:

Input:

Main


              1234567891011
            
package com.example;

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

public class Main {
    public static void main(String[] args) {
        List<String> words = Arrays.asList("apple", "banana", "cherry", "date", "elderberry");
        // Write your code here
    }
}

Use Stream API to find the concatenation of the first two words that have even lengths.

Expected Output:


java

Use filter() and limit() intermediate methods, and the collect() terminal method.


java

Task 5:

Input:

Main


              1234567891011
            
package com.example;

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

public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
        // Write your code here
    }
}

Use Stream API to find the sum of the squares of even numbers in the list.

Expected Output:


java

Use mapToInt() and filter() intermediate methods, and the sum() terminal method.


java

Good job!

If you've completed all the tasks, well done!

Some methods in the tasks may not have been covered earlier. To explore them, open IntelliJ IDEA and check their functionality.

Programming is about continuous learning, so explore new solutions, search online, and refer to documentation when needed.

Everything was clear?

Thanks for your feedback!

Section 4. Chapter 5