如何分割用户输入的字符串

Question

Ok so I have looked at this (question asking how to split a string) however the answer isn't really relevant to my question.

The user will input a weight which is stored in the sqlite DB but I also want the number to show in a TextView below where it was just entered (as the app keeps track of weights over a period of 7 days).

When I try and get the String from my DB its stored as a long String and what I want to do is split that String (I hope I'm making sense!).

I have the following method;

public String[] getWeight() {

    String selectQuery = "SELECT " + DowncroftContract.WEIGHT_VALUE + " FROM " + DowncroftDatabase.WEIGHT_TABLE; //+ " WHERE " + DowncroftContract.WEIGHT_DOGS_ID + " = " + str_dogsId + " ORDER BY " + DowncroftContract.WEIGHT_DATE + " ASC;";
    SQLiteDatabase db = downcroftDatabase.getReadableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);
    String[] data = null;

    if (cursor.moveToFirst()) {
        do {
            results = cursor.getString(cursor.getColumnIndex(DowncroftContract.WEIGHT_VALUE + ""));
            String[] splitString  = results.split("");
            String split1 = splitString[1];
            String split2 = splitString[2];
            DayOne.append(split1);
            DayTwo.append(split2);
        } while (cursor.moveToNext());

    }
    cursor.close();
    return data;
}

Now the above method will split the string up to single figures but I cant seem to figure out how to split the string so that its splitting it for every two figures.

EG User enters 20 presses enter - it then drops down into a TextView called DayOne.

The following day the users enters 24 and presses enter- that then drops down into a TextView called DayTwo.

I think I need an array with possibly a for loop however I am wondering if it is possible to achieve what I want by tweaking what I already have?

Answer 1

You just mean you want to split a String every 2 characters?

Like you have string 123456 and you want 12 , 34 , 56 ?

Try this:

String[] split = result.split("(?<=\\\\G..)");

This is gonna split your String every 2 characters. \\G asserts the position after previous match (or the start of the String if there's not previous match) followed by 2 characters.

Answer 2

[Guy above did basically the same thing, only saw on refresh, snippet will probably still be useful though..]

The part that is splitting your string is String[] splitString = results.split("");

This splits after every "nothing", so in essence, after every character split the string.

Here's a little code snippet I worked together for you...

import java.util.Arrays; //only essential for the Arrays toString bit...

public class Main {

    //Static so it's usable anywhere..
    public static String[] splitStringBy(int everyXLetter, String stringCode)
    {
        // Split the given string by regex, every Xth letter...
        String[] splitIntoSingleElements = stringCode.split("(?<=\\G.{"+everyXLetter+"})");
        // Return it
        return splitIntoSingleElements;
    }

    public static void main(String[] args)
    {
        //Set some string text...
        String text = "askfjaskfjasf";
        //Split and store the string using the above function
        String[] splitText = splitStringBy(2, text);

        //Return it any way you like
        System.out.println(Arrays.toString(splitText)); // [as, kf, ja, sk, fj, as, f]
        System.out.println(splitText[0]); // as
    }
}