Java: Replace a string "python" with "java" and "java" with "python" in a given string

Last update on May 13 2025 12:58:54 (UTC/GMT +8 hours)

Replace "python" with "java" and Vice Versa

Write a Java program to replace a string "python" with "java" and "java" with "python" in a given string.

Input:

English letters (including single byte alphanumeric characters, blanks, symbols) are given on one line. The length of the input character string is 1000 or less.

Visual Presentation:

Sample Solution:

Java Code:

// Importing necessary classes for input/output operations
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;

// Main class named "Main"
class Main {
    
    // Main method to execute the program
    public static void main(String[] args) throws IOException {
        // Creating BufferedReader object to read input from the user
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        
        // Prompting the user to input a string
        System.out.println("Input the string:");
        
        // Reading the input string
        String str1 = br.readLine();
 
        // Replacing occurrences of "java" with "py_thon"
        str1 = str1.replaceAll("java", "py_thon");
        
        // Replacing occurrences of "python" with "java"
        str1 = str1.replaceAll("python", "java");
        
        // Replacing occurrences of "py_thon" with "python"
        str1 = str1.replaceAll("py_thon", "python");
        
        // Outputting the new string
        System.out.println("New string:");
        System.out.println(str1);
    }
} 

Sample Output:

Input the string:
python is more popular than java
New string:
java is more popular than python

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to swap occurrences of two given substrings in a sentence, carefully handling overlapping cases.
• Write a Java program to replace every occurrence of "python" with "java" in a large text file.
• Write a Java program to perform simultaneous substitution of two words in a string without using temporary storage.
• Write a Java program to interchange the positions of two specified words in a sentence while preserving all other text.

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