The first parameter to split is always a regexp even if you write a string (unless that string happens to be a single space).

A single space also results in (the equivalent of) a regex in split. The difference is that the regex is not the string itself (/ /) but /\s+/. Specifying ' ' is an alternaive way of invoking the default which is to split on white space.

Anno

... The difference is that the regex is not the string itself (/ /) but /\s+/

...not to forget the subtle, additional magic of ' ' vs. /\s+/ in the handling of leading whitespace. Compare

my $s = " foo bar baz";

print join("|", split /\s+/, $s), "\n";  # prints  |foo|bar|baz
print join("|", split ' ', $s), "\n";    # prints  foo|bar|baz
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...not to forget the subtle, additional magic of ' ' vs. /\s+/ in the handling of leading whitespace.

Oh right, that too. split() is too clever for its own good by half.

Anno