Rob:
PHP print/echo does not use (). So it should be:
"The value of myvar is $myvar"
The thing with PHP is that if you use "" all variables (word with $) will be replaced by it's value. Using '' and it will print out $myvar instead of the value of $myvar.
You can also do it like this, the way I prefer to do it:
print 'The value of myvar is ' . $myvar
PHP doen't bother about variable types $myvar can be integer, float, string or any type of array. You can do things like:
$var['name'] = 'Dead Glory';
$var['country'] = 'Sweden';
$var[1] = 1;
$var[2] = 2;