Parse String to long with leading zero

Question

Long story short (in Java):

String input= "0888880747;

long convert = Long.parseLong(input);

The value of convert is now: 888880747

How can I parse the String to a long but retain the leading zero?

That makes no sense at all. longs don't have leading zeros, only Strings do. — Hovercraft Full Of Eels, Oct 27 '11 at 15:23
If you want leading zeros you need to store it in a String or format it to a string when printing out. — Shaded, Oct 27 '11 at 15:24

middus · Accepted Answer · 2011-10-27T15:28:29.607

12

You cannot because a long does not have a leading zero. A long is supposed to store integers (the mathematical concept, not int), i.e.

number line

A string of characters like 05 is not an integer, 5 is. What you can do is format a long that holds 5 with a leading zero when you print it, see e.g. java.util.Formatter.

Are you sure you even want to have a long/an integer? What do you want to do with it?

edited Oct 27 '11 at 15:28

answered Oct 27 '11 at 15:23

middus

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Thank you. I suspected as much, but I just wanted to make sure. – Tony Oct 27 '11 at 15:28
it means if it is written like `09` is considered as a string, not an integer and if you convert this into integer, it will give you only '9'. – Farhana Naaz Ansari Nov 12 '18 at 13:12

score 6 · Answer 2 · edited Nov 14 '11 at 03:11

6

You'll have to change it back to a String when you've done your calculations on convert, then:

output = String.format("%06d", convert);

edited Nov 14 '11 at 03:11

T.Rob

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answered Nov 14 '11 at 02:43

JonnyKash

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score 2 · Answer 3 · answered Oct 27 '11 at 15:23

A long is a numeric value. The numeric value of 000001 is no different from 1: It's the exact same number.

So you can't find out how many leading zeroes the initial representation had, once you have a long.

And if you really care about that, then you shouldn't handle the input as a numeric type anyway, but store the String itself, instead.

score 0 · Answer 4 · edited Oct 15 '21 at 02:35

0

You can tweak the code. First get the length of string.

String input  =   "0888880747";

System.out.println(String.format("%0"+input.length()+"d", Long.valueOf(input)))):

The above tweek works but doesn't look good. Better to read the value as String and store in DB as varchar instead of Number if leading zeros matter.

edited Oct 15 '21 at 02:35

Yu Hao

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answered Oct 14 '21 at 16:10

Raghavendra Prasad

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score 0 · Answer 5 · answered Oct 27 '11 at 15:24

0

If your value is a long, then any zeroes to the left (leading) have no mathematical value, therefore, they are stripped off when you do the parsing.

answered Oct 27 '11 at 15:24

pcalcao

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Parse String to long with leading zero

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