How to Replace Spaces with Dashes in Java

In this tutorial, we can use the Java String built-in replace() or replaceAll() methods to replace spaces with dashes (-) easily.

Table of contents:

• 1. Using replace()
• 2. Using replaceAll()
• 3. Which method should we use?
• 4. Real-world Example:
• 5. References

1. Using replace()

The replace() method replaces all occurrences of a specific character.

package com.mkyong;

public class ReplaceSpaceExample {

    public static void main(String[] args) {
        String original = "Hello World from Java";
        String replaced = original.replace(" ", "-");

        System.out.println("Original: " + original);
        System.out.println("Replaced: " + replaced);
    }

}

Output:

Original: Hello World from Java
Replaced: Hello-World-from-Java

2. Using replaceAll()

We can also use replaceAll() if we need to use regular expressions.

package com.mkyong;

public class ReplaceSpaceExampleRegex {

    public static void main(String[] args) {
        String original = "Java Programming Made Easy";
        String replaced = original.replaceAll("\\s+", "-");

        System.out.println("Original: " + original);
        System.out.println("Replaced: " + replaced);
    }

}

Output:

Original: Java Programming Made Easy
Replaced: Java-Programming-Made-Easy

Explanation of \\s+

• \s matches any whitespace character (spaces, tabs, line breaks).
• + means one or more occurrences of the preceding element (\s).

Together, \s+ effectively matches any sequence of whitespace characters, replacing them all with a single dash.

3. Which method should we use?

• Use replace() for simple character replacement (recommended for basic scenarios).
• Use replaceAll() with regex if we want to replace different types of whitespace, such as tabs or multiple consecutive spaces.

4. Real-world Example:

Imagine we are creating SEO-friendly URLs by converting blog titles into URL slugs.

package com.mkyong;

public class URLSlugExample {

    public static void main(String[] args) {
        String blogTitle = "Top 10 Java Programming Tips";
        String urlSlug = blogTitle.toLowerCase().replaceAll("\\s+", "-");

        System.out.println("SEO URL Slug: " + urlSlug);
    }

}

Output:

SEO URL Slug: top-10-java-programming-tips

5. References

• Java String replace() Documentation
• Java String replaceAll() Documentation
• How to split a string in Java – Mkyong.com