Digit Separator in Julia

Question

Coding in Julia shows that using underscore as integer digit separator works in Julia.

x = 1_000_000

and

   x = 1000000

are basically the same thing.

However, I am not able to locate the documentation for this, to read more details. Could anyone point me to that.

Also is digit separation character a common thing in different languages? What are the separator character in C++, java, and Python?

I don't think python has one? I've always just done things like `10**6` — NightShadeQueen, Jul 21 '15 at 17:58
@deviantfan Actually C++14 introduced ' as digit separator I believe. — Baum mit Augen, Jul 21 '15 at 18:08

score 6 · Accepted Answer · edited May 23 '17 at 11:54

6

The standards proposal document for C++14 has a very lengthy discussion on the rationale and possible choices for a digit separator. The considered `, ', _, ::, and (space). Some of the discussion cites other languages. According to the document, _ is also used in Ada, VHDL, Verilog, and possibly Algol68. Underscores also appear to be used in Java 7 (StackOverflow question, proposal). C++ settled on ' as their separator.

Julia hasn't formally documented underscore-separated numeric literals yet, but you can find some information in this GitHub issue (#848) and this julia-dev thread.

It doesn't look like Python has a numeric literal separator.

edited May 23 '17 at 11:54

Community

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answered Jul 21 '15 at 18:42

mbauman

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`_` is also used in [Perl](http://perldoc.perl.org/perldata.html#Scalar-value-constructors). – Vincent Zoonekynd Jul 22 '15 at 00:21
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Note: Algol68 sidestepped the entire issue by allowing a space in a number, for example: 1 million could be 1 000 000, and π could be 3.14159 26535 89793 23846 ... – NevilleDNZ Sep 19 '15 at 23:40

score 3 · Answer 2 · answered Jul 21 '15 at 18:58

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I've just made a pull request to add this to the manual, when you spot things missing it's very easy to add them to the documentation, see:

answered Jul 21 '15 at 18:58

HarmonicaMuse

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Digit Separator in Julia

2 Answers2