How to split a double number by dot into two decimal numbers in Java?

Question

Trying to split a double number into two decimal parts by dot. Like this: 1.9 into 1 and 9; 0.16 into 0 and 16;

Here's what I do, but seems a little redundant, what's the best way to do this?

The origin number will always be like Just 0.x or 1.x or 0.xx or 1.xx and xx > 10

    double d = 1.9;
    int a, b;
    String dString = Double.toString(d);
    String aString = dString.substring(0, 1);

    String bString = dString.substring(2);
    a = Integer.parseInt(aString);
    b = Integer.parseInt(bString);

My way of doing this seems using to much String conversion,which I don't think is very efficient.

What do you expect when the given number is `1.1`, `1.01`, `1.001`, etc? — ntalbs, Jul 15 '14 at 08:22
@ntalbs there's no such numbers in my case .Just 0.x or 1.x or 0.xx or 1.xx and xx > 10 — Johnny Chen, Jul 15 '14 at 08:25

Ruchira Gayan Ranaweera · Accepted Answer · 2014-07-15T09:07:13.560

16

You can try this way too

    double val=1.9;
    String[] arr=String.valueOf(val).split("\\.");
    int[] intArr=new int[2];
    intArr[0]=Integer.parseInt(arr[0]); // 1
    intArr[1]=Integer.parseInt(arr[1]); // 9

edited Jul 15 '14 at 09:07

answered Jul 15 '14 at 08:26

Ruchira Gayan Ranaweera

34,993
17
75
115

@Rucbira.. I am not clear with the `split("\\.")` part.. isn't the `split(".")` part enough? – Kidus Tekeste Feb 07 '20 at 13:04
1

@KidusTekeste see : https://stackoverflow.com/questions/14833008/java-string-split-with-dot. *You need to escape the dot if you want to split on a literal dot* – frianH Oct 15 '20 at 05:52
1

Yes.. I have checked it.. got it now. Thanks @frianH – Kidus Tekeste Oct 15 '20 at 06:31

score 4 · Answer 2 · answered Jul 15 '14 at 08:28

You could treat the double like a string, and split it on the decimal place.

     double d = 13454.92345;
     String bob = Double.toString(d);
     String[] convert = bob.split("\\.");

     int a = Integer.parseInt(convert[0]);
     int b = Integer.parseInt(convert[1]);

     System.out.println(a); // 13454
     System.out.println(b); // 92345

score 2 · Answer 3 · answered Jul 15 '14 at 08:22

To get the decimal part as an int is not really following any standards, so you are stuck with your special solution for that. Getting the value before the decimal point can be simplified to a simple cast though:

double d = 1.9;
int a, b;
String dString = Double.toString(d);
String bString = dString.substring(2);
a = (int) d;
b = Integer.parseInt(bString);

Note that the substring() and parseInt() fails if the number is 10 or bigger though. You might want to change the substring() call to something like:

String bString = dString.split("\\.")[1];

nobalG · Answer 4 · 2014-07-15T08:33:04.657

1

double num=12.5;
String str=Double.toString(num);
String strarray[]=str.split("\\.");

Now strarray[0] will be holding 12, and strarray[1] will be having 5.You can convert them into integers by writing following code:

int num1=Integer.parseInt(strarray[0]);
int num2=Integer.parseInt(strarray[1]);

edited Jul 15 '14 at 08:33

answered Jul 15 '14 at 08:25

nobalG

4,544
3
34
72

Make sure that you split on "." WITH "\\." – tudoricc Jul 15 '14 at 08:26

Bohemian · Answer 5 · 2014-07-15T08:40:09.213

Here's a two line version:

int a = (int)d;
int b = Integer.parseInt((d + "").split("\\.", 2)[1]).replaceAll("^$", "0"));

The first part is easy - just cast to int, which automatically chops off any decimal part of the number.

The second part is easiest with a Strimg approach - split the string version on a dot and use the second part. Note the addition of "" which generates a string, and the handling of the edge case of there being no decimal part, where 3 as a double prints as 3. - if the result is a blank (guaranteed by the second parameter to split) which is then converted to a zero.

score 1 · Answer 6 · edited Jul 15 '14 at 09:29

1

  double d = 1.9;
  String str = Double.toString(d);
  String strArray[] = str.split("\\.");

  int a = Integer.parseInt(strArray[0]);
  int b = Integer.parseInt(strArray[1]);
  System.out.print(a + " - " + b);

Try this. This will work.

edited Jul 15 '14 at 09:29

Andrey

6,526
3
39
58

answered Jul 15 '14 at 08:33

bumbumpaw

2,522
1
24
54

Patrik Oldsberg · Answer 7 · 2014-07-15T09:01:15.750

0

This solution should work for almost any length of the fractional part and doesn't use strings. For example the accepted answer doesn't work for 0.16

double d = 123.456

long a = (long) d;
double f = d - a;

while (Math.abs((long) f - f) > 0.000001) f *= 10;

long b = (long) f;

// a = 123
// b = 345

edited Jul 15 '14 at 09:01

answered Jul 15 '14 at 08:55

Patrik Oldsberg

1,540
12
14

@JrChen Well, it used to not work, now it's using `String` instead – Patrik Oldsberg Jul 16 '14 at 07:02

score 0 · Answer 8 · answered Oct 26 '17 at 17:04

0

Here is another approach:

double d=1.9;
int a;
int b;

a = (int) d/10;
b = (int) d%10;

System.out.print("a");
System.out.print("b");

answered Oct 26 '17 at 17:04

Richard Muñoz

187
3
12

Loyola · Answer 9 · 2019-04-14T19:39:59.423

0

    double dub=1234.5678987;//Variable to be manipulated
    long lon=0; //To store before decimal point.    
    short sh=0;//To store after decimal point.  
    int deci=10000; //to 4 decimal places   
    lon=(int)dub;// get the integer part of the number stored in long   
    sh=(short)((dub-(double)lon)*deci);//deci to required decimal places.
    System.out.println(""+lon+"."+sh);

edited Apr 14 '19 at 19:39

answered Apr 14 '19 at 19:34

Loyola

1
1

score -1 · Answer 10 · answered Jul 15 '14 at 08:24

-1

I tried a split on "." and then just parse the string for integers.

        String a="";
        double x = 2.4;
        a=x+"";
        String [] v =a.split("\\.");
        int before = Integer.parseInt(v[0]);
        int after = Integer.parseInt(v[1]);

answered Jul 15 '14 at 08:24

tudoricc

709
1
12
31

you gotta make `a` first – Scary Wombat Jul 15 '14 at 08:26
I did make the "a" first – tudoricc Jul 15 '14 at 08:27
where is it initialized? – Scary Wombat Jul 15 '14 at 08:27
Thank you for that,as I was writing the code in I deleted more than I should have.Sorry again – tudoricc Jul 15 '14 at 08:28
This is a not very elegant way of putting a double in a String variable – Marco Jul 15 '14 at 08:35
I do realise this but as I said it was the first thing that came to mind – tudoricc Jul 15 '14 at 08:37
Try `String a = Double.toString(x)`! – isnot2bad Jul 15 '14 at 09:01

How to split a double number by dot into two decimal numbers in Java?

10 Answers10

Linked