How to Filter Elements of a List based on a Condition in Java

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How to Filter Elements of a List based on a Condition in Java ?

Answer

To filter elements of a list based on a condition in Java, you can use the Stream API along with lambda expressions.

✐ Examples

1 Filter Integers Greater Than a Threshold

In this example,

We create a list named numbers with integer values.
We use the stream() method to create a stream of elements from the list.
We use the filter method along with a lambda expression to filter elements greater than a threshold value.
Finally, we collect the filtered elements into a new list.

Java Program

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

public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
        int threshold = 3;
        List<Integer> filteredNumbers = numbers.stream()
                                            .filter(num -> num > threshold)
                                            .collect(Collectors.toList());
        System.out.println("Filtered list: " + filteredNumbers);
    }
}

Output

Filtered list: [4, 5]

2 Filter Strings Containing a Substring

In this example,

We create a list named words with string values.
We use the stream() method to create a stream of elements from the list.
We use the filter method along with a lambda expression to filter elements containing a specific substring.
Finally, we collect the filtered elements into a new list.

Java Program

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

public class Main {
    public static void main(String[] args) {
        List<String> words = Arrays.asList("apple", "banana", "cherry", "date", "elderberry");
        String substring = "erry";
        List<String> filteredWords = words.stream()
                                        .filter(word -> word.contains(substring))
                                        .collect(Collectors.toList());
        System.out.println("Filtered list: " + filteredWords);
    }
}

Output

Filtered list: [cherry, elderberry]

Summary

In this tutorial, we learned How to Filter Elements of a List based on a Condition in Java language with well detailed examples.

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How to Filter Elements of a List based on a Condition in Java

How to Filter Elements of a List based on a Condition in Java ?

Answer

✐ Examples

1 Filter Integers Greater Than a Threshold

Java Program

Output

2 Filter Strings Containing a Substring

Java Program

Output

Summary

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