PHP 101: Building Strings

We need to build a string from dynamic content. We’ll have a string literal and we need to insert some content into it at the appropriate spot. How do we do it?

There are a couple of techniques you can use in PHP.

Concatenate Strings – Embedded Function

You can concatenate strings together using the dot operator. You can use string literals, variables, and functions. For example, let’s say we need to insert a translated string into a user-defined attribute of a shortcode.

$post_meta .= ' [post_terms taxonomy="department" before="' . __( 'Department: ', 'teambios' ) . '"]';

How does this work?

1. The WordPress translation function runs first to get the string value.
2. The left string literal is concatenated with the translated “Department: ” string.
3. Then it’s concatenated with the closing string literal.
4. The new string is concatenated to the string value in the variable.
5. The new string is assigned back to the variable.

Watch the video to see how this works and to work through the steps.

Use Placeholders and a Formatted String Pattern

The other strategy is to use placeholders in a formatted string pattern. Then run that through a function that replaces out each placeholder with a string value. PHP provides sprintf() and printf(). We’ll use sprintf.

The placeholder is the %s character string. The PHP construct looks for that placeholder and then matches it up with its argument. It then processes the argument and inserts the value to replace the placeholder.

Watch the video to see how this works.

This approach is prevalent and very popular. It’s my preferred approach.. Why?

• You can see the resultant string pattern without having to figure it out. #EasierToRead
• If you have more than one embed, it’s definitely easier to read and maintain.