PHP 101: Concatenating Assignment Operator

The term “concatenating” means that we are smooshing two strings together by appending the one on the right to the one on the left. The result is a new string value.

For example, let’s say that a variable $post_meta has a value of '[post_categories] [post_tags]'. You want to append another shortcode to the end of it. How do you do that?

There are two different ways to achieve this and make an assignment.

Long Hand Approach

To concatenate an existing variable’s string value to some value you are processing, you have a couple of choices in PHP. You can do it with the long hand approach, like this:

$post_meta = $post_meta . ' [post_terms taxonomy="department"]';

where the shortcode’s string literal is smooshed together to the end of the string value in the variable $post_meta. Then the new string is assigned back to the variable. That’s the long hand version.

Short Hand Approach

PHP provides you with a concatenating assignment operator as a shorthand approach:

$post_meta .= ‘ [post_terms taxonomy=”department”]’;

This code works the same as the full version; however, it’s more condensed. It eliminates the repetitious repeating of the variable. Therefore, this approach is more readable and maintainable.

This approach is very popular and prevalent! Make sure you understand it completely!

What’s the Sequence and Result?

Let’s walk through the processing and look at the result.

Step 1: Concatenate

First the variable’s value and string literal are concatenated to form a new string value of:

'[post_categories] [post_tags] [post_terms taxonomy="department"]';

Step 2: Assignment

The next step is to assign the new string to the variable $post_meta, which means the value it represents is changed to:

$post_meta = '[post_categories] [post_tags] [post_terms taxonomy="department"]';

This Episode

In this episode, let’s talk about the process of concatenating. Then we’ll walk through how each of these approaches works. Finally, we’ll see the results.