Why Printing “B” in Java is Slower Than “#”? NetBeans Performance Issue Explained

If you’ve ever noticed that printing the letter “B” in Java is significantly slower than printing “#” in NetBeans, you’re not alone. This unexpected slowdown has puzzled many developers. In this post, we’ll explore the root cause, discuss its implications, and provide practical solutions to optimize console output performance.

The Issue: Identical Code, Drastically Different Performance

Consider two Java programs that generate a 1000×1000 matrix. The first program prints “#” while the second replaces “#” with “B”. Strangely, the second program takes 30 times longer to execute in NetBeans, despite nearly identical code.

Code Snippet 1 (Fast with “#”)

import java.util.Random;

Random r = new Random();
for (int i = 0; i < 1000; i++) {
    for (int j = 0; j < 1000; j++) {
        if (r.nextInt(4) == 0) {
            System.out.print("O");
        } else {
            System.out.print("#"); // Completes in ~8.5 seconds
        }
    }
    System.out.println();
}

Code Snippet 2 (Slow with “B”)

import java.util.Random;

Random r = new Random();
for (int i = 0; i < 1000; i++) {
    for (int j = 0; j < 1000; j++) {
        if (r.nextInt(4) == 0) {
            System.out.print("O");
        } else {
            System.out.print("B"); // Takes ~259 seconds in NetBeans
        }
    }
    System.out.println();
}

The Root Cause: NetBeans’ Word-Wrapping Behavior

The slowdown is caused by how NetBeans handles console line wrapping. Here’s why:

1. Character Classification:
   • # is treated as a non-word character.
   • B is considered a word character (part of a readable word).
2. Console Line Wrapping:
   • When the output reaches the console’s width limit, NetBeans looks for a word boundary before breaking the line.
   • With #, it breaks immediately since non-word characters don’t require additional processing.
   • With B, NetBeans searches further for a valid break point, causing excessive processing time and performance degradation.

Performance Benchmark: NetBeans vs. Eclipse

The issue is specific to NetBeans, as shown in benchmark tests:

Conclusion: NetBeans struggles with long sequences of word characters, while Eclipse handles them efficiently.

Fixing the Slowdown in NetBeans

Solution 1: Insert Line Breaks Manually

Forcing line breaks reduces processing time:

for (int j = 0; j < 1000; j++) {
    System.out.print("B");
    if (j % 50 == 0) { // Break line every 50 characters
        System.out.println();
    }
}

Solution 2: Adjust NetBeans Console Settings

1. Navigate to Tools > Options > Editor > Formatting.
2. Change Line Wrap setting from “At Whitespace” to “Anywhere”.
   • This prevents excessive word-boundary searches, reducing lag.

Solution 3: Use a Different IDE

Eclipse and command-line terminals handle console output more efficiently, making them better choices for output-heavy applications.

Why This Doesn’t Affect All Systems

• Command-Line Terminals: Linux/macOS terminals don’t perform the same word-wrapping checks as NetBeans.
• Online Compilers: Platforms like Ideone.com are optimized for speed and avoid IDE-specific bottlenecks.

Conclusion

The extreme slowdown when printing “B” in NetBeans highlights how IDE settings can impact performance. By understanding the word-wrapping behavior and applying simple fixes, you can eliminate this issue and ensure smooth execution of console-heavy Java programs.

Key Takeaways

✅ NetBeans’ word-wrapping logic is the culprit.
✅ Switching to Eclipse or adjusting settings can resolve the issue.
✅ Manually inserting line breaks prevents excessive processing.

Keywords: Java print performance, NetBeans console slow, word-wrapping issue, System.out.print slow, Eclipse vs NetBeans, Java IDE optimization.