How to Remove Zero-Width Space (ZWSP) Characters in Java

Introduction:

Zero-width space (ZWSP), represented by \u200B, is an invisible character that can appear in your string, especially when copying, pasting, or fetching text. ZWSP can disrupt string processing, affecting operations such as searching and comparing.

In this article, we will explore how to detect and remove ZWSP from strings in Java

For Example, If you have the string "Hello WELLCOME\u200B", it appears as "Hello WELLCOME", but there is an invisible ZWSP between the two words.

First I tried the trim() method to remove the zwsp but it Won’t Work, because the trim() method is commonly used to remove leading and trailing spaces from strings.

To remove the ZWSP, you can use the following two approaches:

First Approach By using replace all():

This method allows you to replace every occurrence of a character (or pattern) using a regular expression.

Example:

public class RemoveZWSP {
    public static void main(String[] args) {
        // Example string containing ZWSP
        String input = "Hello WELLCOME\u200B";
        // Remove all ZWSP
        String removedString = input.replaceAll("\u200B", "");
        System.out.println("Before: [" + input + "]");
        System.out.println("After: [" + removedString + "]");
    }
}
Output:
Before: [Hello WELLCOME\u200B]
After: [Hello WELLCOME]

Note: Useful when working with regular expressions, but slightly slower due to the overhead of regex processing.

Second Approach By using replace ():

This method is faster since it directly replaces the character without regex processing.

Example:

String input = "Hello WELLCOME\u200B";
String removedString =input.replace("\u200B", "");

Output
Before: [Hello WELLCOME\u200B]
After: [Hello WELLCOME]

Note: Faster and more efficient when you only need to replace specific characters without regex.

Conclusion

Invisible characters like Zero-Width Space (ZWSP) can create hidden challenges in your Java applications. By using the replaceAll() or replace() methods, you can easily remove ZWSP and ensure your string processing remains smooth and error-free.