Question

Where is the difference between the following two Statements?

print "surname=" ,$myVal, "\n";

and

print "surname=" .$myVal. "\n"

I’ve tested them and both return the same result. Is there even a difference?

Thanks

Answer 1

A Perl programmer would probably write that as:

print "surname=$myVal\n";

It does look like it’s doing the same thing, doesn’t it? And in your example it does do the same thing. The difference is more obvious if you replace the scalar variable with an array.

my @var = qw(some data);

print "value=", @var, "\n";
print "value=". @var. "\n";

The difference is in the number of arguments that are passed to the print function. If you use the concatenation operator (.) then your arguments are concatenated together into one string and print gets a single argument. If you use the comma, then print gets a list of arguments.

Of course, it’s possible to mix the methods in the same print call.

print "surname=" ,$myVal . "\n";

Another nice example is to use the return value from localtime.

print 'The time is ', localtime, "\n";
print 'The time is '. localtime, "\n";