PHP and printing out whitespace?

Question

I was wondering how can I print out whitespace in the following code below.

<?php echo "$first_name", "$last_name" ; ?>

Answer 1

<?php 
echo "$first_name $last_name"; 
?>

Answer 2

Just, well, add whitespace to your output?

<?php echo "$first_name $last_name with     some    whitespace" ; ?>

Sometimes, it the obvious answer is right - even in PHP!

Answer 3

Notice that when you use ' any var aren't display, with " does.
So, good is:
<?php echo "$first_name $last_name" ; ?>
bad
<?php echo '$first_name $last_name' ; ?>

Answer 4

If you want to concatenate several strings without the double quotes (e.g. when using single quotes):

$string = $first_name . ' ' . $last_name; // The dot is a concatenation operator

Answer 5

If you want to keep using commas:

<?php echo  $first_name, ' ', $last_name; ?>