Java: Return a string with the characters of the index position 0,1,2, 5,6,7, ... from a given string

Last update on May 21 2025 12:50:10 (UTC/GMT +8 hours)

97. Chars at Indices 0-2, 5-7, etc.

Write a Java program to return a string with characters at index positions 0,1,2,5,6,7, ... from a given string.

Visual Presentation:

Sample Solution:

Java Code:

import java.util.*;

// Define a class named Main
public class Main {
  
  // Method to extract pairs of characters from the string
  public String pairsToReturn(String stng) {
    String fin_str = ""; // Initialize an empty string to store the modified string
    
    // Loop through the string with a step size of 5
    for (int i = 0; i < stng.length(); i += 5) {
      int end = i + 3; // Set the end index for extracting pairs
      
      // Check if the calculated end index is greater than the string's length
      if (end > stng.length()) {
        end = stng.length(); // If yes, update the end index to the string's length
      }
      
      // Extract a pair of characters from the string and append it to the final string
      fin_str = fin_str + stng.substring(i, end);
    }
    return fin_str; // Return the modified string
  }

  // Main method to execute the program
  public static void main(String[] args) {
    Main m = new Main(); // Create an instance of the Main class

    String str1 = "w3resource.com"; // Given string
    // Display the given string and the new string after extracting pairs
    System.out.println("The given string is: " + str1);
    System.out.println("The new string is: " + m.pairsToReturn(str1));
  }
}

Sample Output:

The given string is: w3resource.com
The new string is: w3rour.co

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to extract characters from a string at specific index intervals (e.g., indices 0-2, 5-7, etc.).
• Write a Java program to form a new string by picking characters at positions that match a given pattern.
• Write a Java program to generate a string using characters from fixed index blocks from the original string.
• Write a Java program to create a new string by selecting characters from designated positions in the input string.

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