Hello, and welcome to today's PHP lesson! We are going to unravel an intriguing challenge that will refine our skills in string manipulation. This lesson will place particular emphasis on loops. Prepare yourself for an exciting adventure as we explore how to extract odd-indexed characters from each word in a sentence, but only if the word has an even number of characters. Sounds exciting? Let's dive in!

The task we'll be demonstrating is as follows: We will work with a string representing a sentence in which words are separated by spaces. Your challenge involves creating a PHP function that identifies the odd-indexed characters of words that have an even number of characters and then combines these characters into a single string, maintaining the order in which they appeared in the sentence.

Consider this example: "PHP8 programming language is versatile." The word PHP8 has 4 characters (an even number), and we'll select the odd-indexed characters from this word, specifically, H and 8. Similarly, we'll select a, g, a, and e from language, from , and , , , , and from . We'll skip the word because it has an odd length.