Hyphenated Words Exercise

Inside the directory you created for this course on PHP, create a new folder called Exercise-13-Hyphenated-Words and put the .php solution files for this exercise within it.

The description clearly says to keep on asking the user to enter a hyphenated word unless the value is valid, i.e. unless the value contains a hyphen (-) character in it.

This reminds us of a loop, specifically a while loop, whose condition is set to check if the input value doesn't contain a hyphen (-) character.

First, let's set up the input prompt:

<?php

echo 'Enter a hyphenated word: ';
$word = rtrim(fgets(STDIN));

And now, let's set up the while loop:

<?php

echo 'Enter a hyphenated word: ';
$word = rtrim(fgets(STDIN));

while (!str_contains($word, '-')) {
   // The error message.
   echo 'Invalid input', "\n\n";

   echo 'Enter a hyphenated word: ';
   $word = rtrim(fgets(STDIN));
}

As you can see here, the input prompt code has been repeated inside the body of the while loop.

For now, this isn't a problem at all since the code is short and simple, and so there's not going to be a big issue even if we repeat it. Had it been a complex piece of code, we would've considered another better way.

Anyways, moving on, once the loop exits, we know that the value of $word is valid. Likewise, we could proceed with extracting out the individual words from $word after the while loop.

For the output, $word is split into a list at each hyphen (-) character using explode(), and then each element of this list is printed out using a for loop, after printing a blank line:

<?php

echo 'Enter a hyphenated word: ';
$word = rtrim(fgets(STDIN));

while (!str_contains($word, '-')) {
   echo 'Invalid input', "\n\n";
   echo 'Enter a hyphenated word: ';
   $word = rtrim(fgets(STDIN));
}

// At this point, $word is valid. Likewise, we can proceed with the output

echo "\n";
$words = explode('-', $word);
for ($i = 0; $i < count($words); $i++) {
   echo $words[$i], "\n";
}

This completes our exercise!