CodeGym/Help with Java Tasks/unable to start

Level 9

Islamabad

24.09.2018
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12comments

unable to start

Question about the task

The end

Java Syntax, Level 7, Lesson 12

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level 7, lesson 12, name: the end. **stuck at "how to take input untill user types 'the end'"..?

public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        ArrayList<String> s = new ArrayList<String>();

        string ss = "the end";
        for(int i=0; i<; i++)
        {

        }

        //write your code here
    }

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gery

Level 9 , Islamabad, Pakistan

24 September 2018, 02:27

level 7, lesson 12, name: the end. **stuck at "how to take input untill user types 'the end'"..?

Ankush Rajput

Level 25 , Bhopal, India

24 September 2018, 02:43

Compare the input String with "the end". If comparision with "the end" returns true, don't execute further statements and exit. You can use String.equals("the end") to compare. Edit : - Its only "end" in question and not "the end".

gery

Level 9 , Islamabad, Pakistan

24 September 2018, 02:54

public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        ArrayList<String> s = new ArrayList<String>();

        //string ss = "the end";
        //for(int i=0; i<; i++)
        //{
        while( ( s = reader.readLine()) != null){
         if (! (s.equals("end")))
         s.add(reader.readLine());

      //  }

        //write your code here
    }
    for(int i = s.size() - 1; i>=0; i--)
    {
        System.out.println(s);
    }

gery

Level 9 , Islamabad, Pakistan

24 September 2018, 02:55

compile bounce error on line 9 and if i remove reader.readline() from line 11 then this too

Ankush Rajput

Level 25 , Bhopal, India

24 September 2018, 03:11

useful

Many mistakes here. In while loop you are writing s = reader.readLine() but you haven't decalred string s (remember .readLine() method returns a string). Since you've put the return value of readLine into string, you don't have to do s.add(reader.readline()) ,it will store next line into arrayLIst. Simple do list.add(s). Also, since you are naming S as string, name arraylist as something else. Also, why are you printing the list in reverse order ? You have to print it from 0 to list.size(). And, you cannot just print list like println(list). You have to use the get() method of ArrayList to get each element and print. like list.get(i).

gery

Level 9 , Islamabad, Pakistan

24 September 2018, 03:48

i mis-read the last requirement, thanx for the correction

gery

Level 9 , Islamabad, Pakistan

24 September 2018, 03:49

code runs but show NULL with following inputs sd sd end

gery

Level 9 , Islamabad, Pakistan

24 September 2018, 03:49

public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        ArrayList<String> ss = new ArrayList<String>();

        String s;
        while( ( s = reader.readLine()) != null){
         if (! (s.equals("end")))
         ss.add(ss);

      //  }

        //write your code here
    }
    for(int i = 0; i<ss.size(); i++)
    {
        System.out.println(s);
    }

        //write your code here
    }

Ankush Rajput

Level 25 , Bhopal, India

24 September 2018, 03:52

in line 9, you are adding arraylist to arraylist. It should be ss.add(s). You have to add string to list. In line 17, you have to print elements of arraylist. you are simply printing string s. It should be ss.get(i).

gery

Level 9 , Islamabad, Pakistan

24 September 2018, 03:56

i corrected code as per ur comment. i mis-read my own code repeatedly

gery

Level 9 , Islamabad, Pakistan

24 September 2018, 03:56

runs show [sd, sd] [sd, sd] further my comment limit has reached and i cant further put any comment..(if u add me back to ur network since i cant msg u dre because of limit too)

public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        ArrayList<String> ss = new ArrayList<String>();

        String s;
        while( ( s = reader.readLine()) != null){
         if (! (s.equals("end")))
         ss.add(s);

      //  }

        //write your code here
    }
    for(int i = 0; i<ss.size(); i++)
    {
        System.out.println(ss);
    }

        //write your code here
    }

Ankush Rajput

Level 25 , Bhopal, India

24 September 2018, 04:01

solution

Still not correct. In line 17, you cannot simply print list like that. you have to call get method. println(ss.get(i)). If you want to print list like you are doing then use another version of from loop. for(String x : ss) System.out.println(x);