What is the difference between "value" and "values" in PHP form input elements?
The difference between "value" and "values" in PHP form input elements is that "value" is used to set the initial value of a single input field, while "values" is used to set the initial values of multiple input fields. When using "value", only one value can be set for that specific input field, whereas "values" can set multiple values for multiple input fields at once.
// Using "value" to set the initial value of a single input field
<input type="text" name="username" value="<?php echo $username; ?>">
// Using "values" to set the initial values of multiple input fields
<input type="checkbox" name="hobbies[]" value="reading" <?php if(in_array('reading', $hobbies)) echo 'checked'; ?>> Reading
<input type="checkbox" name="hobbies[]" value="cooking" <?php if(in_array('cooking', $hobbies)) echo 'checked'; ?>> Cooking
<input type="checkbox" name="hobbies[]" value="painting" <?php if(in_array('painting', $hobbies)) echo 'checked'; ?>> Painting