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PHP

Matt Borgman
Matt Borgman
18,313 Points
Posted by Matt Borgman
Matt Borgman
18,313 Points

PHP String Interpolation

I am trying to better understand string interpolation when in comes to PHP. My question is why can you parse a variable with double quotes when it is by itself or within a string as follows: 

$name = "Matt";
echo "My name is $name";

But, if you want to echo a string and HTML you have to use string concatenation, such as:

$name = "Matt";
echo "<h1>" . $name . "</h1>";

1 Answer

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

Hi Matt,

Your second example can be done the same way as the first example. Did you see something that suggested you couldn't do it?

Matt Borgman
Matt Borgman
18,313 Points
Matt Borgman
Matt Borgman
18,313 Points

I'm trying to remember if I tried it previously and couldn't. What jogged my memory is on the PHP track, "Build a basic PHP website" course, the instructor does a foreach block as so:

    <ul>
      <?php 
      foreach($catalog as $item) {
        echo "<li>" . $item . "</li>";
      }
      ?>
    </ul>

But I tried it as you suggest and it worked both ways. If I did ever try the other way and have it not work it must have been a syntax error. Thank you for the response and helping me make sense of things.

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

There are some situations where you can't simply include the variable as in your examples. Your first example is considered simple syntax but there's a complex syntax where the variable has to be surrounded with curly braces.

You can read more about that here: http://php.net/manual/en/language.types.string.php#language.types.string.parsing

In the complex syntax section you'll see some examples of when you might need curly braces.

It will come in handy on this code challenge: https://teamtreehouse.com/library/php-arrays-and-control-structures/php-arrays/multidimensional-arrays

I'm not sure if you've taken that course already or plan to.

If you decide to use interpolation on that one then the curly braces will come in handy since it's a multi-dimensional array.

Matt Borgman
Matt Borgman
18,313 Points
Matt Borgman
Matt Borgman
18,313 Points

Thank you for the further explanation and the resources, I will definitely check those out!