Java IntStream of() Method

The IntStream.of() method in Java, part of the java.util.stream.IntStream interface, is used to create an IntStream from specified values. This method is overloaded to support creating a stream from a single int or from an array of ints.

Table of Contents

1. Introduction
2. of() Method Syntax
3. Understanding of()
4. Examples
   • Basic Usage with Single Value
   • Basic Usage with Multiple Values
5. Real-World Use Case
6. Conclusion

Introduction

The of() method is a static method that creates an IntStream from the specified values. This method is particularly useful when you need to quickly create a stream from a known set of values.

of() Method Syntax

There are two overloads of the of() method:

1. Creating a stream from a single int value:

static IntStream of(int t)

2. Creating a stream from an array of int values:

static IntStream of(int... values)

Parameters:

• t: A single int value.
• values: An array of int values (varargs).

Returns:

• An IntStream containing the specified values.

Throws:

• This method does not throw any exceptions.

Understanding of()

The of() method provides a simple and concise way to create an IntStream from specified values. This can be useful for testing, quick data manipulations, and scenarios where the stream values are known beforehand.

Examples

Basic Usage with Single Value

To demonstrate the usage of of() with a single value, we will create an IntStream from a single int value and print it.

Example

import java.util.stream.IntStream;

public class OfSingleValueExample {
    public static void main(String[] args) {
        IntStream intStream = IntStream.of(5);

        // Print the elements of the stream
        intStream.forEach(System.out::println);
    }
}

Output:

5

Basic Usage with Multiple Values

To demonstrate the usage of of() with multiple values, we will create an IntStream from an array of int values and print them.

Example

import java.util.stream.IntStream;

public class OfMultipleValuesExample {
    public static void main(String[] args) {
        IntStream intStream = IntStream.of(1, 2, 3, 4, 5);

        // Print the elements of the stream
        intStream.forEach(System.out::println);
    }
}

Output:

1
2
3
4
5

Real-World Use Case

Creating a Stream for Testing

In real-world applications, the of() method can be used to create a stream for testing purposes. This allows developers to easily create streams with known values for unit tests and other testing scenarios.

Example

import java.util.stream.IntStream;

public class TestingExample {
    public static void main(String[] args) {
        IntStream testStream = IntStream.of(10, 20, 30, 40, 50);

        // Perform a test operation on the stream
        int sum = testStream.sum();

        // Print the result
        System.out.println("Sum of test stream: " + sum);
    }
}

Output:

Sum of test stream: 150

Conclusion

The IntStream.of() method is used to create an IntStream from specified values, either a single int or an array of ints. This method is particularly useful for quickly creating streams with known values. By understanding and using this method, you can efficiently create and work with streams of integer values in your Java applications.