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

Java Regular Expression: Exercise-30 with Solution

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

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

Flowchart :

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

Java Code Editor:

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Java: Tips of the Day

What is the best way to filter a Java Collection?

Java 8 (2014) solves this problem using streams and lambdas in one line of code:

List<Person> beerDrinkers = persons.stream()
    .filter(p -> p.getAge() > 16).collect(Collectors.toList());

Use Collection#removeIf to modify the collection in place. (Notice: In this case, the predicate will remove objects who satisfy the predicate):

persons.removeIf(p -> p.getAge() <= 16);

lambdaj allows filtering collections without writing loops or inner classes:

List beerDrinkers = select(persons, having(on(Person.class).getAge(),
    greaterThan(16)));

Ref: https://bit.ly/3uwYid6