Replace words in string with * except spaces between words

Question

0.00/5 (No votes)

See more:

I have written a code in which I am trying to print the word "bad" as it is and other words I am replacing with *. The code is as follows:

import java.util.*;
import java.io.*;
import java.lang.*;

    public class wordreplaceabhinew
    {
        
       
  
     public static void main(String[]args)
        {
            Scanner sc=new Scanner(System.in);
            String comment;
            System.out.println("Enter a comment:");
            comment=sc.nextLine();
           
 
   
    for (int i = 0; i < comment.length(); i++) {
       
if(comment.charAt(i)!=' ')
{
     
      if(comment.charAt(i)=='b')
      {
         
          if(comment.charAt(i+1)=='a')
          {
             
             if(comment.charAt(i+2)=='d')
             {
              comment=comment.substring(i,i+3);
               
             }
            
          }

          else 
          {
              System.out.print("*");

          }
   
      } 
      
System.out.print("*");
         
}
else
{
    System.out.print(" ");
    
}


        
   
}
  System.out.print(comment);
 


              
        }  
    }

For example my input is "I am bad"
O/p should be "* ** bad"
But instead I am getting "* ** *bad"
I want to understand where I am going wrong?

What I have tried:

import java.util.*;
import java.io.*;
import java.lang.*;

    public class wordreplaceabhinew
    {
        
       
  
     public static void main(String[]args)
        {
            Scanner sc=new Scanner(System.in);
            String comment;
            System.out.println("Enter a comment:");
            comment=sc.nextLine();
           
 
   
    for (int i = 0; i < comment.length(); i++) {
       
if(comment.charAt(i)!=' ')
{
     
      if(comment.charAt(i)=='b')
      {
         
          if(comment.charAt(i+1)=='a')
          {
             
             if(comment.charAt(i+2)=='d')
             {
              comment=comment.substring(i,i+3);
               
             }
            
          }

          else 
          {
              System.out.print("*");

          }
   
      } 
      
System.out.print("*");
         
}
else
{
    System.out.print(" ");
    
}


        
   
}
  System.out.print(comment);
 


              
        }  
    }

Posted 24-Feb-23 0:03am

Abhinav Kishore M

Updated 24-Feb-23 0:38am

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard Deeming · Answer 1 · 2023-02-24T00:21:00

Solution 1

First problem: your loop variable ranges across all valid character indices within the value. But within the loop, you try to access characters at index i+1 and i+2. If, for example, your string ends with "Jacob", you will get an exception trying to access a character past the end of the string.

Second problem: you write out either a '*' or a ' ' for everything in the string apart from "bad", and then write out the remaining "bad"s at the end. If, for example, your input was "This is very bad; your teacher forbade you from doing this.", you would output: "**** ** *** ; **** ******* **** *** **** ***** *****badbad", which is clearly wrong.

Except you wouldn't, because of the third problem: as soon as you find "bad", you throw away the rest of the string. So that input would actually produce, "**** ** **** bad".

Except that's still not quite right, because of the fourth problem: you're writing out a '*' for everything that isn't a space. So when you find your first "bad", you write out a '*', terminate the loop, and the write out "bad".

Stop and think what you're trying to do. Stop modifying the input string, and write out "bad" as part of the loop.

It's your homework assignment, so no code; but you want to implement something like this:

If the current character is a space, write a space;
Otherwise, if the current character is "b", and the index is at least three less than the length, and the next two characters are "a" and "d", write "bad";
Otherwise, write "*";

Posted 24-Feb-23 0:21am

Richard Deeming

Updated 24-Feb-23 0:22am

v3

Comments

Abhinav Kishore M 24-Feb-23 6:55am

Otherwise, if the current character is "b", and the index is at least three less than the length, and the next two characters are "a" and "d", write "bad";
I am confused in this thing

Richard Deeming 24-Feb-23 6:59am

You're currently testing whether the current character is "b" and the next two characters are "a" and "d". But you're not testing whether there are two more characters to check.

As I said, if your input string ends with "b" or "ba", then your code will throw an exception.

if (i < comment.length() - 2 && comment.charAt(i) == 'b' && comment.charAt(i + 1) == 'a' && comment.charAt(i + 2) == 'd')
{
    System.out.print("bad");
}

Abhinav Kishore M 24-Feb-23 7:25am

Thank u Richard. But now I am facing one more issue.
O/p is now coming as:
* ** bad**I am bad
The code I have here is:
for (int i = 0; i < comment.length(); i++) {

if(comment.charAt(i)!=' ')
{

if (i < comment.length() - 2 && comment.charAt(i) == 'b' && comment.charAt(i + 1) == 'a' && comment.charAt(i + 2) == 'd')
{
System.out.print("bad");
}
else
{
System.out.print("*");

}
}
else
{
System.out.print(" ");

}

}

Richard Deeming 24-Feb-23 7:37am

You'll also need to add 2 to the loop index when you find "bad".

if (i < comment.length() - 2 && comment.charAt(i) == 'b' && comment.charAt(i + 1) == 'a' && comment.charAt(i + 2) == 'd')
{
    System.out.print("bad");
    i += 2;
}

Abhinav Kishore M 24-Feb-23 7:43am

Thanks Richard but even though I am getting bad and words have been replaced by equal number of *, I am also getting o/p as under:
* ** badI am bad
The sentence is repeated again.
How to resolve this issue?

Richard Deeming 24-Feb-23 7:44am

Sounds like you haven't removed the System.out.print(comment); line from after the for loop.

Abhinav Kishore M 24-Feb-23 7:46am

Thanks Richard

Abhinav Kishore M 24-Feb-23 8:04am

Hi I wrote this code correctly and for many inputs it was showing correct o/p. But for this i/p:
Bad code is being shown. Bad comment is not to be shown. How many bad is there?
It is showing o/p as:
*** **** ** ***** ****** *** ******* ** *** ** ** ****** *** **** ** *bad* ******
Can we make this code possible for ALL inputs?

Looks like the other bad is being replaced by *. No idea why?

Richard Deeming 24-Feb-23 8:13am

Your code is only checking for lower-case "bad" - both other instances have an upper-case "B" at the start, so they won't be matched.

If you want to allow upper or lower case, then you need to check both. You'll probably want to match the case of the input too:

if (i < comment.length() - 2 && (comment.charAt(i) == 'b' || comment.charAt(i) == 'B') && (comment.charAt(i + 1) == 'a' || comment.charAt(i + 1) == 'A') && (comment.charAt(i + 2) == 'd' || comment.charAt(i + 2) == 'D')) {
    System.out.print(comment.substring(i, i + 3));
    i += 2;
}

For your input, that produces:

Bad **** ** ***** ****** Bad ******* ** *** ** ** ****** *** **** bad ** ******

Abhinav Kishore M 24-Feb-23 8:16am

Thanks

Graeme_Grant · Answer 2 · 2023-02-24T00:38:00

Solution 2

Additional to what Richard wrote, I suggest chunking the string: How to Split a String in Java with Delimiter - Javatpoint[^] and doing word comparisons, then rejoining/concatenating.

How to compare words: String Comparison in Java - javatpoint[^]

Posted 24-Feb-23 0:38am

Graeme_Grant

Updated 24-Feb-23 0:39am

v2

Comments

Abhinav Kishore M 24-Feb-23 6:56am

Did u mean this:

if(comment.charAt(i)!=' ')
{
    String s1="bad";
    if(s1==comment.substring(i, i+3))
    {
        System.out.print(s1);
    }
    else 
    {
        System.out.print("*");
     }
 }    
else
{
    System.out.print(" ");
}

Graeme_Grant 24-Feb-23 7:08am

I am not going to write it for you, however here is the logic:

1. Split the words in an array
2. loop over each word and compare with "bad"
3. if not equals bad, replace word with equal number of '*'
4. concat/join result string (result = result + word + " ")
5. go to 2.
6. print result

ps: take the time to read the content in the link that I provided for you.

Abhinav Kishore M 24-Feb-23 7:30am

I have resolved this issue as under:
for (int i = 0; i < comment.length(); i++) {

if(comment.charAt(i)!=' ')
{

if (i < comment.length() - 2 && comment.charAt(i) == 'b' && comment.charAt(i + 1) == 'a' && comment.charAt(i + 2) == 'd')
{
System.out.print("bad");
}
else
{
System.out.print("*");

}
}
else
{
System.out.print(" ");

}

}
But now o/p is coming as under:
* ** bad**I am bad

Abhinav Kishore M 24-Feb-23 8:14am

Hi I wrote this code correctly and for many inputs it was showing correct o/p. But for this i/p:
Bad code is being shown. Bad comment is not to be shown. How many bad is there?
It is showing o/p as:
*** **** ** ***** ****** *** ******* ** *** ** ** ****** *** **** ** *bad* ******
Can we make this code possible for ALL inputs?

Looks like the other bad is being replaced by *. No idea why?