How to replace every second character in a sequence

[Antonio Gridushko]

Hello, everyone!

I need to understand which class and method in Java I should use to replace every, for example, 3d letter  in any sentence.

For example,  in this sentence: "This period was good" I want to replace every 3 d letter... with "r" exactly.... so at the end of compilation I should have


"Thrs perior war gord"

And if the letter in this sentense consists from only one letter- there is no changing.

[Junilu Lacar]

Welcome to the Ranch!

What have you tried so far? Please show us your code.

Also, see the links in my signature below for tips on how to ask questions in these forums.

[praveen kumaar]

Hi Antonio,welcome to ranch!
do you have tried to write a pseudo code,if not please take a piece of paper and write it.

Hint:-you can use "split"and "toCharArray" method of String class.
----->API link for more information.

[Norm Radder]

which class and method  

Since the sentence is contained in a String, start by looking at the String class.  Also the StringBuilder and StringBuffer classes would be useful.
See the API doc:  http://docs.oracle.com/javase/8/docs/api/index.html

[Campbell Ritchie]

Welcome again
Did you really say to replace every 3rd letter in a sequence, or did you mean in a String? Did you know there is a class specifically designed for altering Strings? It even has a method for replacing characters. That would be another possible solution.

[Antonio Gridushko]

Campbell Ritchie wrote:Welcome again
Did you really say to replace every 3rd letter in a sequence, or did you mean in a String? Did you know there is a class specifically designed for altering Strings? It even has a method for replacing characters. That would be another possible solution.

Thanks everyone, I found my answer

import java.util.*;

public class Main {
    //Blablablatext
    public static void main(String[] args) {

        System.out.println("Enter text string");
        Scanner sc1 = new Scanner(System.in);
        String text = sc1.nextLine();
        String[] strArr= text.split(" ");

        System.out.println("Enter number");
        int n = 0;
        Scanner sc2 = new Scanner(System.in);
        try{
         n = sc2.nextInt();}
        catch (InputMismatchException fg)
    {
        System.out.print("Not number" );
        return;
    }

        System.out.println("Enter symbol");
        Scanner sc3 = new Scanner(System.in);
        char symbol = sc3.next().charAt(0);

        for(int i = 0; i<strArr.length; i++) {


            String newStrArr [] = new String[strArr.length];
            if(strArr[i].length()>n)
            {
               newStrArr[i] = strArr[i].substring(0,n) + symbol + strArr[i].substring(n+1);
            }
            else{
             newStrArr[i] = strArr[i];
            }
            System.out.println(newStrArr[i]);
        }

    }
}

[praveen kumaar]

Antonio,Good job!
please use code tag,it will make your code look better and readable to others.their are lot of features on ranch for posting,so utilize them.

Thanks,
kind regards,
Praveen.

[Norm Radder]

The sample results: "Thrs perior war gord" showed some replacements but I'm not sure what rules were used.
For me replacing every third letter in:  

"This period was good"  
-1231-231231-231-2312

would replace the letters above the 3s shown above.  If the spaces are not considered letters.

[Carey Brown]

When I run your code it doesn't replace every 2nd character.

Enter text string
aaaaaaaaa bbbbbbb
Enter number
2
Enter symbol
x
aaxaaaaaa
bbxbbbb