Objective
Extract out individual words from a hyphenated word.
Description
Ask the user to input a hyphenated word by the following input prompt message:
Once the word is given, extract out the constituent words from it, and print each on a new line.
Shown below is an example:
If the input word is not hyphenated i.e. there is not a hyphen (-) in it, print 'Invalid input!', and keep asking the user to enter a hyphenated string, as shown above, until the correct input is received.
Shown below is a demonstration:
Note the blank lines over here.
If the input value is invalid, print 'Invalid input!' and then leave a blank line before asking the user to input again. If the input value is valid, leave a blank line before printing out all the constituent words in the hyphenated word.
Hints
Hint 1
Use the explode() string function to extract out the individual words from the given input value.
New file
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.
Solution
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!
