Java: Find and replace a word in a given string

Last update on May 24 2025 12:59:35 (UTC/GMT +8 hours)

13. Python Detection in String

Write a Java program to find the word Python in a given string, if the word Python present in the string return Java otherwise return C++. Ignore case sensitive.

Sample Solution-1:

Java Code:

import java.util.*;

public class test {
 
   public static void main(String[] args) {
	   
	    String text = "python";
		System.out.println("Original string: "+text);
		System.out.println("New string: "+validate(text));
		text = "JavaScript";
		System.out.println("\nOriginal string: "+text);
		System.out.println("New string: "+validate(text));
		text = "PYTHON";
		System.out.println("\nOriginal string: "+text);
		System.out.println("New string: "+validate(text));
        }

   public static String validate(String text) {
	   	String str = text.toLowerCase();
		if (str.contains("python")) {
			return "Java";
		} 
		return "C++";
   }
}

Sample Output:

Original string: python
New string: Java

Original string: JavaScript
New string: C++

Original string: PYTHON
New string: Java

Pictorial Presentation:

Flowchart :

Sample Solution-2:

Java Code:

public class test {
 
   public static void main(String[] args) {
	   
	    String text = "python";
		System.out.println("Original string: "+text);
		System.out.println("New string: "+validate(text));
		text = "JavaScript";
		System.out.println("\nOriginal string: "+text);
		System.out.println("New string: "+validate(text));
		text = "PYTHON";
		System.out.println("\nOriginal string: "+text);
		System.out.println("New string: "+validate(text));
        }

   public static String validate(String text) {
	   return text.matches("(?i).*(?<=python).*") ? "Java" : "C++";
   }
}

Sample Output:

Original string: python
New string: Java

Original string: JavaScript
New string: C++

Original string: PYTHON
New string: Java

Flowchart :

For more Practice: Solve these Related Problems:

• Write a Java program to search for the word "Python" in a string ignoring case, and return "Java" if found, otherwise "C++".
• Write a Java program to implement a case-insensitive keyword check that conditionally returns one of two predefined values.
• Write a Java program to design a method that compares a target keyword in different cases and returns alternate outputs.
• Write a Java program to test a string for the presence of "Python" and conditionally replace it with a programming language name.

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