I want even and odd indexed elements from an array to be stored in separate ArrayLists

Question

I've declared two ArrayLists and one array which name is str. I want to store even indexed elements of array in number ArrayList and odd indexed in name ArrayList.

Please help me. Thank you.

 import java.util.Scanner;
 import java.util.*;

 public class Que1 {

  public static void main(String[] args) 
  {

   int a=0;
   String[] str=new String[1000];

   List<String> name = new ArrayList<>();
   List<Integer> number = new ArrayList<>();

   Scanner sc=new Scanner(System.in);
   a=sc.nextInt();


   for(int i=0;i<=a;i++)
      {
         String ns=sc.nextLine();
         str=ns.split(" ");  
            for(int j=0;j<str.length;j=j+2)
                {
                     name.add(str[j]);
                     Collections.sort(name);
                }

            for(int k=1;k<str.length;k=k+2)
                 {
                     int add=Integer.parseInt(str[k]);
                     number.add(add);
                     Collections.sort(number);
                 }
      }

   for(int i=0;i<str.length;i++)
      {            
            String valueName = name.get(i);
            String valueNumber = number.get(i).toString();
            System.out.print(valueName+ " ");
            System.out.print(valueNumber+ " ");
      }      
  }
}

output:: here number Arraylist is first printing rather than name ArrayList and In name arrayList one white space also print i don't know why and last element of name ArrayList is also not printing. can anyone find solution

2
a 11 b 22 c 33
d 44 e 55 f 66
  11 a 22 b 33 c 44 d 55 e 66 BUILD SUCCESSFUL (total time: 20 seconds)

`i <= name.size()` The list has a size of `4`, so the highest index you can access is `3`. Change it to `i < name.size()` . — Lukas Rotter, Aug 15 '16 at 13:08
Try debugging. This way you can find out when the index becomes too big for the array. — MrSmith42, Aug 15 '16 at 13:14
Also `int j=0` and `int k=0` in for loop initializer seems a bit odd. Shouldn't it be `int j=1` and `int k=0`? — ZbyszekKr, Aug 15 '16 at 13:24
Does it work with my answer? I tried to improve your odd/even check — Marco Santarossa, Aug 16 '16 at 00:59
@SaintThread it's work but name ArrayList one element is not printing in output i don't know why — , Aug 16 '16 at 04:39

score 1 · Answer 1 · edited Aug 17 '16 at 11:12

1

You are trying to retrieve the item in the size place but since the counting of items starts from 0, the last item is at size() - 1.

Meaning, you for should write it like this:

for (int i = 0; i < name.size(); i++)

edited Aug 17 '16 at 11:12

Idos

15,053
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answered Aug 15 '16 at 13:11

Tzach Solomon

688
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27

Marco Santarossa · Answer 2 · 2016-08-15T14:36:42.327

1

You can write:

for(int j=0; j != str.length; j++) {
    if (j % 2 == 0) { // Even
        number.add(str[j]); 
    } else { // Odd
        name.add(str[j]);
    }
}

And to print the arrays replace the <= with <

edited Aug 15 '16 at 14:36

answered Aug 15 '16 at 14:13

Marco Santarossa

4,058
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49

I want even and odd indexed elements from an array to be stored in separate ArrayLists

2 Answers2