I think you are confusing PHP syntax and the syntax of some other (object oriented?) programming language that you already know. You apparently are not aware of the significance of the terminating semi-colon in PHP (so I guess that this other language isnt C++ or Java).
Your loop does not make sense. From what I see, you intend to loop through an array of textarea contents, so why use strlen() at all?
strlen() only makes sense when you have an element of the array, and so want to check how long is the given string.
Your code might be something like:
for ($i = 0; $i < $number_of_textareas; ++$i) {
if (strlen($textarea[$i]) < 50) {
echo "you need to write at least 50 characters";
}
}
Of course, in reality I would probably use a foreach loop instead of a for loop, I would use $_POST['Fieldvalue'] instead of $textarea, and I would handle the error feedback differently.
