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regexperl

Is there a one-liner to get the first element of a split?

Instead of writing:

@holder = split /\./,"hello.world"; 
print @holder[0];

is it possible to just do a one-liner to just get the first element of the split? Something like:

print (split /\./,"hello.world")[0]

I get the following error when I try the second example:

print (...) interpreted as function at test.pl line 3.
syntax error at test.pl line 3, near ")["
Solution

  • You should have tried your hunch. That’s how to do it.

    my $first = (split /\./, "hello.world")[0];

    You could use a list-context assignment that grabs the first field only.

    my($first) = split /\./, "hello.world";

    To print it, use

    print +(split /\./, "hello.world")[0], "\n";

    or

    print ((split(/\./, "hello.world"))[0], "\n");

    The plus sign is there because of a syntactic ambiguity. It signals that everything following are arguments to print. The perlfunc documentation on print explains.

    Be careful not to follow the print keyword with a left parenthesis unless you want the corresponding right parenthesis to terminate the arguments to the print; put parentheses around all arguments (or interpose a +, but that doesn't look as good).

    In the case above, I find the case with + much easier to write and read. YMMV.