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author | Jarkko Hietaniemi <jhi@iki.fi> | 2001-04-29 15:55:39 +0000 |
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committer | Jarkko Hietaniemi <jhi@iki.fi> | 2001-04-29 15:55:39 +0000 |
commit | 928753ea20dfcc4327533c22eecccbc215e82fee (patch) | |
tree | c1ddf60e7c74061943aa1556daf62f093b023379 /pod/perldata.pod | |
parent | aa58aa353209e3416c78e241b039154fdfd9415b (diff) | |
download | perl-928753ea20dfcc4327533c22eecccbc215e82fee.tar.gz |
Changed the underscore/undebar syntax in numeric constants;
now any grouping will do, as long as the underscores are not
consecutive (so "zero-grouping" is out), and they do not begin
or end the integer or fractional parts.
p4raw-id: //depot/perl@9905
Diffstat (limited to 'pod/perldata.pod')
-rw-r--r-- | pod/perldata.pod | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/pod/perldata.pod b/pod/perldata.pod index 48cd0e7cf5..42e3af723c 100644 --- a/pod/perldata.pod +++ b/pod/perldata.pod @@ -271,22 +271,24 @@ integer formats: 12345 12345.67 .23E-10 # a very small number + 3.14_15_92 # a very important number 4_294_967_296 # underscore for legibility 0xff # hex + 0xdead_beef # more hex 0377 # octal 0b011011 # binary -You are allowed to use an underscore in numeric literals for legibility, -but in decimal numeric literals (those written in base 10, not -necessarily with a fractional part), digits may only be grouped in -threes. For decimal numeric literals containing a fractional part, -this applies only to the part before the decimal point; the fractional -part (but not the exponent, if given!) may contain underscores -anywhere you feel it enhances legibility. Binary, octal, and -hexadecimal numeric literals may contain underscores in any place -- -so you could, for example, group binary digits by threes (as for a -Unix-style mode argument such as 0b110_100_100) or by fours (to -represent nibbles, as in 0b1010_0110) or in other groups. +You are allowed to use underscores (underbars) in numeric literals for +legibility, as long as the underscores are spaced at least one digit +apart, and they do not begin or end the integer or fractional part. +You could, for example, group binary digits by threes (as for +a Unix-style mode argument such as 0b110_100_100) or by fours +(to represent nibbles, as in 0b1010_0110) or in other groups. + +(Note that if you try to begin a number with an underscore, it won't +even be understood as a number, it will be understood as a bareword, +which depending on the context may mean for example a string constant, +a function call, or a filehandle.) String literals are usually delimited by either single or double quotes. They work much like quotes in the standard Unix shells: |