CodeGym/Help with Java Tasks/one and only one condition is not getting executed ,can a...

Level 10

Bangalore

23.01.2019
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one and only one condition is not getting executed ,can any one tell where is the problem?

Question about the task

R or L

Java Syntax, Level 7, Lesson 9

Under discussion

where is the mistake?

1. Create a list of words and populate it yourself.
2. The fix method should:
2.1. remove all words containing the letter "r" from the list
2.2. duplicate all words containing the letter "l".
2.3. if a word contains both "r" and "l", then leave it unchanged.
2.4. don't do anything to other words.

For example:
rose lyre love

Output:
lyre love love

Requirements:

The program must not read data from the keyboard.
The fix method should remove all words containing the letter "r" from the list. There is an exception: words containing both "r" and "l" should be left alone.
The fix method must duplicate words containing the letter "l" (add another instance of this word to the list). There is an exception: words containing both "l" and "r" should not be duplicated.
The fix method should not do anything with words that contain both "l" and "r".
The fix method should not do anything with words that don't contain either "l" or "r".

package com.codegym.task.task07.task0716; import java.util.ArrayList; /* R or L */ public class Solution { public static void main(String[] args) throws Exception { ArrayList<String> list = new ArrayList<String>(); list.add("rose"); // 0 list.add("love"); // 1 list.add("lyre"); // 2 list = fix(list); for (String s : list) { System.out.println(s); } } public static ArrayList<String> fix(ArrayList<String> list) { // write your code here int si=list.size(); for(int i=0;i<si;i++){ if(list.get(i).contains("r") && list.get(i).contains("l")){ continue; } else if(list.get(i).contains("r")){ list.remove(i); i=i-1; } else if(list.get(i).contains("l") && !list.get(i).contains("r")){ list.add(list.get(i)); } } return list; } }

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Ashraf Khalifa

Level 9 , Coventry, United Kingdom

21 May 2021, 22:38

Hi, the index for the duplicate string that you want to add should be the next index after the word it is duplicating. Also you can re-arrange your test conditions to check for strings with "r" and not "l" first then test for strings with "l" and not "r" next this will eliminate the need to have a third test condition for strings with both "r" and "l". hope this helps.

hanumohan

Level 25 , San Jose, United States

9 April 2020, 21:20

for(int i=0;i<si;i++){
          System.out.print("Loop cycle: " + i + " - Checking value: '" + list.get(i)+"' ");
          if(list.get(i).contains("r") && list.get(i).contains("l")){
              System.out.println("Contains both r & l, leaving unchanged");
              continue;
          }
          else if(list.get(i).contains("r")){
              System.out.println("Contains only r, removing from list, (i = i-1)");
              list.remove(i);
              i=i-1;
          } else if(list.get(i).contains("l")) {
              System.out.println("contains only l, duplicating");
              list.add(list.get(i));
          }
          System.out.print("Values of list: ");
          for(int j = 0; j < list.size(); j++){
              System.out.print(j+":"+list.get(j)+", ");
          }
          System.out.println();
      }

try to minimize loop

for (int i = 0; i < list.size(); i++){
           if (list.get(i).contains("r") && !list.get(i).contains("l")){
               list.remove(i);
               i--;
           }
          else if (list.get(i).contains("l") && !list.get(i).contains("r")){
               String element = list.get(i);
              list.add(i,element);
              i++;

           }
       }

Guadalupe Gagnon

Level 37 , Tampa, United States

23 January 2019, 16:03

useful

I left your code unchanged, just added some sys.out statements to see what is happening in your loop. Copy and paste this over your fix method. It should help you see the problem. Once the output is correct, make sure to delete all the sys.out statements before validating:

public static ArrayList<String> fix(ArrayList<String> list) {

        int si=list.size();

        for(int i=0;i<si;i++){
            System.out.print("Loop cycle: " + i + " - Checking value: '" + list.get(i)+"' ");
            if(list.get(i).contains("r") && list.get(i).contains("l")){
                System.out.println("Contains both r & l, leaving unchanged");
                continue;
            }
            else if(list.get(i).contains("r")){
                System.out.println("Contains only r, removing from list, (i = i-1)");
                list.remove(i);
                i=i-1;
            } else if(list.get(i).contains("l")) {
                System.out.println("contains only l, duplicating");
                list.add(list.get(i));
            }
            System.out.print("Values of list: ");
            for(int j = 0; j < list.size(); j++){
                System.out.print(j+":"+list.get(j)+", ");
            }
            System.out.println();
        }
        System.out.println("METHOD CONCLUDED");
        return list;
    }

srikanth

Level 10 , Bangalore, India

24 January 2019, 04:46

many many thanks dude....here output is showing like this: love lyre love love

srikanth

Level 10 , Bangalore, India

24 January 2019, 05:10

by checking manually i came to know that if we decrement (list.size -1 here:si-1) i got desired list but it is working only in run not in verify it is still showing that 3rd condition is not satisfied.

Guadalupe Gagnon

Level 37 , Tampa, United States

24 January 2019, 14:35

the output of your code should be with the inputs (in order) rose, love, lyre: love love lyre

srikanth

Level 10 , Bangalore, India

25 January 2019, 05:52

hi with all necessary changes code is able to work in Run but in verify it is not getting passed...

Syed Tayyab ul Mazhar

Level 12 , Karachi, China

28 January 2019, 07:50

It's not stated in the conditions, that the duplicate must be next to the element being duplicated. I've verified my solution by providing rose, love, lyre as inputs, for which the output I got in IntelliJ was love, lyre, love..

Syed Tayyab ul Mazhar

Level 12 , Karachi, China

28 January 2019, 07:53

Just decrementing variable i won't work, you need to do one more similar thing.

hanumohan

Level 25 , San Jose, United States

9 April 2020, 21:17

line 17 list.add(list.get(i)); replace to list.add(i , list.get(i)); Before: love lyre love love Result : love love lyre