Java: Insert a dash between an upper case letter and a lower case letter in a given string

Last update on May 24 2025 12:59:25 (UTC/GMT +8 hours)

30. Dash Between Upper and Lower Case

Write a Java program to insert a dash (-) between an upper case letter and a lower case letter in a string.

Sample Solution:

Java Code:

public class test { 
   public static void main(String[] args) {	   
	    String text = "Python Exercises";
		System.out.println("Original string: "+text);
		System.out.println("Insert a dash between an upper case letter and a lower case letter in the said string:\n"+validate(text));
		text = "The quick brown Fox jumps over the lazy Dog.";
		System.out.println("\nOriginal string: "+text);
		System.out.println("Insert a dash between an upper case letter and a lower case letter in the said string:\n"+validate(text));	
		text = "java exercises";
		System.out.println("\nOriginal string: "+text);
		System.out.println("Insert a dash between an upper case letter and a lower case letter in the said string:\n"+validate(text));
        }

   public static String validate(String text) {
	   return text.replaceAll("(?<=[A-Z])(?=[a-z])", "-");
    }
}

Sample Output:

Original string: Python Exercises
Insert a dash between an upper case letter and a lower case letter in the said string:
P-ython E-xercises

Original string: The quick brown Fox jumps over the lazy Dog.
Insert a dash between an upper case letter and a lower case letter in the said string:
T-he quick brown F-ox jumps over the lazy D-og.

Original string: java exercises
Insert a dash between an upper case letter and a lower case letter in the said string:
java exercises

Pictorial Presentation:

Flowchart :

For more Practice: Solve these Related Problems:

• Write a Java program to scan a string and insert a dash between any uppercase letter immediately followed by a lowercase letter.
• Write a Java program to implement a regex that detects an uppercase letter followed directly by a lowercase letter and inserts a dash.
• Write a Java program to modify a string by adding dashes at boundaries where an uppercase letter is adjacent to a lowercase letter.
• Write a Java program to split a string at uppercase-lowercase transitions and then reassemble it with a dash inserted between the parts.

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Java Code Editor:

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