During recent coding, using PHP, I found that the explode function behaves in a non-ideal way (for me) when trying to split an empty string:

<?php

$res = explode(",", "");
print_r($res);

?>

produces:

Array
(
    [0] =>
)

I was expecting (needing?) an empty array. After thinking about it a bit more, it is clear that returning a single empty string is a logical return value. However, different languages have different returns for this special case. Python (2.6.4 and 3.1.2) are both like PHP (5.3.5), but Perl (5.10.1) behaves differently:

For PHP:

<?php
function test_explode($txt)
{
    print("Exploding '$txt' to give [" );
    $sep = "";
    $res = explode(",", $txt);
    foreach ($res as $elt)
    {
        print "$sep'$elt'";
        $sep = ", ";
    }
    print "]\n";

}

test_explode("a,b");
test_explode(",");
test_explode("");

?>

produces:

Exploding 'a,b' to give ['a', 'b']
Exploding ',' to give ['', '']
Exploding '' to give ['']

For Python:

def test_split(txt):
    print("Splitting '%s' to give %s" % (txt, txt.split(",")))

test_split("a,b")
test_split(",")
test_split("")

produces:

Splitting 'a,b' to give ['a', 'b']
Splitting ',' to give ['', '']
Splitting '' to give ['']

For Perl:

sub test_split
{
    my $txt = shift;
    my @res = split(",", $txt);
    print("Splitting '$txt' to give [");
    my $sep = "";
    foreach my $elt (@res)
    {
        print "$sep'$elt'";
        $sep = ", ";
    }
    print "]\n";
}


test_split("a,b");
test_split(",");
test_split("");

produces:

Splitting 'a,b' to give ['a', 'b']
Splitting ',' to give []
Splitting '' to give []