4.3. Single-Character Strings
Don't write one-character strings in visually ambiguous ways .
Character strings that consist of a single character can present a variety of problems, all of which make code harder to maintain.A single space in quotes is easily confused with an empty string:
$separator = ' ';
Like an empty string, it should be specified more verbosely:
$separator = q{ }; # Single space
Literal tabs are even worse (and not just in single-character strings):
$separator = ' '; # Empty string, single space, or single tab???
$column_gap = ' '; # Spaces? Tabs? Some combination thereof?
Always use the interpolated \t form instead:
$separator = "\t";
$column_gap = "\t\t\t";
Literal single-quote and double-quote characters shouldn't be specified in quotation marks either, for obvious aesthetic reasons: '"', "\", '\'', "'". Use q{"} and q{'} instead.You should also avoid using quotation marks when specifying a single comma character. The most common use of a comma string is as the first argument to a join:
my $printable_list = '(' . join(',', @list) . ')';
The ',', sequence is unnecessarily hard to decipher, especially when:
my $printable_list = '(' . join(q{,}, @list) . ')';
is just as easy to write, and stands out more clearly as being a literal. See the "Constants" guideline later in this chapter for an even cleaner solution.
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