JAVA PROGRAM • LEVEL 16 — LAMBDAS, STREAMS & MODERN JAVA

Use a Parallel Stream Safely in Java

Learn use a parallel stream safely in java with a complete, compiler-ready Java 17 example.

Advancedparallel()Associative reduction

PROBLEM UNDERSTANDING

Input and expected output

Sample input
No input required
Sample output
5050

COMPLETE JAVA 17 PROGRAM

Complete Java 17 implementation

java-parallel-stream.java
Open in compiler
import java.util.stream.*;
class Main{public static void main(String[] args){int sum=IntStream.rangeClosed(1,100).parallel().sum();System.out.println(sum);}}

GUIDED CODE TOUR • NOT LIVE EXECUTION

Study the program line by line

Use the real compiler button above to run and debug with different inputs.

CURRENT STEP

Select Start to walk through the important lines.

SELECTED LINE

No line selected

EXPECTED OUTPUT FOR THE SAMPLE

5050
0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

  1. Initialize the deterministic sample values used for use a parallel stream safely in java.
  2. Apply parallel() and Associative reduction in the order shown by the program.
  3. Print the final result and compare it with the documented sample output.

This Java 17 example demonstrates parallel() and Associative reduction through a complete, executable program. The values are intentionally small so students can trace each statement, verify the output, and then modify the example safely in the online compiler.

EFFICIENCY

Time and space complexity

Time complexity

O(n)

Auxiliary space

O(n)

DEBUGGING CHECKLIST

Common mistakes

Check this

Keep the class name Main and the entry method signature public static void main(String[] args) when using the online compiler.

Check this

Use parallel() with compatible Java types; Java checks types and method signatures at compile time.

Check this

Java is case-sensitive, and every statement that requires a semicolon must end with one.

Try it yourself

Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.