Perl

use Digest::MD5 qw(md5_hex);

print "1: foo => ", md5_hex("foo"), "\n";
print "2: bar => ", md5_hex("bar"), "\n";
print "3: 123 => ", md5_hex(123), "\n";
print "4: empty => ", md5_hex(""), "\n";
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Output

1: foo => acbd18db4cc2f85cedef654fccc4a4d8
2: bar => 37b51d194a7513e45b56f6524f2d51f2
3: 123 => 202cb962ac59075b964b07152d234b70
4: empty => d41d8cd98f00b204e9800998ecf8427e
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PHP

<?
echo "1: foo => ", md5("foo"), "\n";
echo "2: bar => ", md5("bar"), "\n";
echo "3: 123 => ", md5(123), "\n";
echo "4: empty => ", md5(""), "\n";
?>
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Output

1: foo => acbd18db4cc2f85cedef654fccc4a4d8
2: bar => 37b51d194a7513e45b56f6524f2d51f2
3: 123 => 202cb962ac59075b964b07152d234b70
4: empty => d41d8cd98f00b204e9800998ecf8427e
[download]

gav^