Question: I am just beginning to learn PHP and I am using **PHP for the Web: Visual Quickstart Guide 4th edition** and I have a question about a script I learned in the book and just wrote.

This is the code of the script:

```
     print '<p>Thank you, ' .$title.$name. ' for your comments.</p>
    <p>You stated that you found this example to be "'.$response.'" and added:<br />'
    .$comments.'</p>';

    print "<p>Thank you, $title $name for your comments.</p><p>You stated that you found this example to be '$response' and added:<br/>$comments</p>";

```

This script is just displaying some data from an HTML form that is pulled via POST.

What is the correct way to do this? I am having a lot of trouble understanding `'` vs `"` in this context.

The second example is the one out of the book and the first example is one that I found how to do after trying to understand the ' vs " question. In regards to this, where is a good location to find information about `'` vs `"`.

Answer: 
In PHP, variables inside double quoted strings are replaced with their values. This does not happen in single quoted strings.

For example:

```
$make = 'Nisaan';
$model = 'Altima';

echo 'I drive a $make $model.'; // I drive a $make $model.
echo "I drive a $make $model."; // I drive a Nissan Altima.

```

You can also use the concatenation operator `.` to use the value of a variable in a string:

```
echo 'I drive a '.$make.' '.$model.'.'; // I drive a Nissan Altima.

```

For more on PHP strings, check the PHP docs: <http://php.net/manual/en/language.types.string.php>
Double quotes are using to parse variables inside the string. If you use `"Hi, $name"`, it'll correctly parse the variable to, for example, `Hi, AlexBeau`. If you'd use `'Hi, $name'`, it'd output `Hi, $name`.

If you are asking about case where you use `.` to concatenate strings, it doesn't really matter. Just use it according to rules I mentioned earlier.

Single quotes should be faster though, as there's no parsing going on.