Java splitting string using delimiter and store to different array

Question

I was having some problem when trying to split string with delimiter and store to array. So basically I have a main array with input like this:

1564095_SINGLE_true, 1564096_SINGLE_true

What I am trying to do is split the string with delimiter and store to two different array. Below as how I loop thru the main array:

String arrayA = [];
String arrayB = [];
for(int i = 0; i < selectedRecord.length; i++) {
   log.debug("HEY " + selectedRecord[i]);
   String tempRecord = selectedRecord[i];
}

My desired output will be:

arrayA: 1564095_SINGLE, 1564096_SINGLE
arrayB: true, true

But I have no idea on how to split it. Any ideas? Thanks!

String arrayA = []? That is not valid Java code.

MC Emperor
– MC Emperor

2021-08-03 07:29:22 +00:00
Commented Aug 3, 2021 at 7:29 — MC Emperor
– MC Emperor, Commented Aug 3, 2021 at 7:29

Tim Biegeleisen · Accepted Answer · 2021-08-03 07:10:06Z

2

Here is one approach which splits in the input on the following regex pattern:

_(?!.*_)

This splits the input string on only the last underscore character. We can try iterating your collection of inputs, and then populating the two arrays.

List<String> inputs = Arrays.asList(new String[] {"1564095_SINGLE_true", "1564096_SINGLE_true"});
String[] arrayA = new String[2];
String[] arrayB = new String[2];
int index = 0;
for (String input : inputs) {
    arrayA[index] = input.split("_(?!.*_)")[0];
    arrayB[index] = input.split("_(?!.*_)")[1];
    ++index;
}
System.out.println("A[]: " + Arrays.toString(arrayA));
System.out.println("B[]: " + Arrays.toString(arrayB));

This prints:

A[]: [1564095_SINGLE, 1564096_SINGLE]
B[]: [true, true]

answered Aug 3, 2021 at 7:10

Tim Biegeleisen

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7 Comments

QWERTY Over a year ago

Hi can check with you what does the new String[2] means?

Tim Biegeleisen Over a year ago

@BlackMamba new String[2] is the RHS of the statement used to create a string array of size 2.

QWERTY Over a year ago

I see I see thanks so much! but lets say if I do not have the size of the array? what should I specify there

Tim Biegeleisen Over a year ago

... then don't use arrays, use a list instead :-)

QWERTY Over a year ago

Hmm but if I switch it to List, the following part will hv problem arrayA[index] = input.split("(?!.*)")[0];

|

DKS · Accepted Answer · 2021-08-03 07:19:24Z

2

Does this help? Assuming you can apply basic checks (null, array length, etc)

  String[] selectedRecord = {"1564095_SINGLE_true", "1564096_SINGLE_true"};
    String[] arrayA = new String[selectedRecord.length];
    String[] arrayB = new String[selectedRecord.length];
    for (int i = 0; i < selectedRecord.length; i++) {
        arrayA[i] = selectedRecord[i].substring(0, selectedRecord[i].lastIndexOf("_"));
        arrayB[i] = selectedRecord[i].substring(selectedRecord[i].lastIndexOf("_")+1);
    }
    System.out.println(Arrays.asList(arrayA));
    System.out.println(Arrays.asList(arrayB));

answered Aug 3, 2021 at 7:19

DKS

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Comments

Vish Garad · Accepted Answer · 2021-08-03 07:39:28Z

check below code

import java.util.*;
public class MyClass {
public static void main(String args[]) {
  
  String str="1564095_SINGLE_true, 1564096_SINGLE_true";
  System.out.println(str);
  String arr[]=str.split(",");
  ArrayList<String> arr1=new ArrayList();
   ArrayList<String> arr2=new ArrayList();
  
  for(int i=0;i<arr.length;i++)
  {
     String temp[]= arr[i].split("_");
   
     for(int j=0;j<temp.length;j++)
     {
        
         
         
       
            if(j==2)
             {
                 arr2.add(temp[j]);
             }
             else
            {
                 arr1.add(temp[j]);
            }
         
         
     }
     
  }
  System.out.println(arr1);
  System.out.println(arr2);
}

}

SidK · Accepted Answer · 2021-08-03 07:39:59Z

0

    String selectedRecord[] = { "1564095_SINGLE_true", "1564096_SINGLE_true" };
    String[] arrayA = new String[selectedRecord.length];
    String[] arrayB = new String[selectedRecord.length];
    for(int i = 0; i < selectedRecord.length; i++) {
       String tempRecord = selectedRecord[i];
       int size = tempRecord.split("_").length;
       arrayB[i]= tempRecord.split("_")[size-1];
       arrayA[i]= tempRecord.replace("_"+arrayB[i], "");
    }

    System.out.println("ArrayA: "+ Arrays.asList(arrayA));
    System.out.println("ArrayB: "+ Arrays.asList(arrayB));

Output:
ArrayA: [1564095_SINGLE, 1564096_SINGLE]
ArrayB: [true, true]

answered Aug 3, 2021 at 7:39

SidK

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Comments

Mubariz Mirzayev · Accepted Answer · 2021-08-03 17:32:48Z

0

Hi you can do something like this. Get the last index of the delimiter and substring the string.

String arrayA = [];
String arrayB = [];
for(int i = 0; i < selectedRecord.length; i++) {
   int end = selectedRecord.lastIndexOf("_");
   arrayA[i] = selectedRecord.substring(0, end);
   arrayB[i] = selectedRecord.substring(end+1);
}

Of course here should be some datatype conversions. If you want to store "true"/"false" inside of the boolean array.

edited Aug 3, 2021 at 17:32

answered Aug 3, 2021 at 7:14

Mubariz Mirzayev

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1 Comment

DKS Over a year ago

int end = selectedRecord.indexOf("_"); This should be lastIndexOf.

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