Switch statement doesn't gives out the cases I want - php

Question

I have 2 problems here. First, I don't know how to use preg_match for filtering out digits and special characters, only letter and a & should be allowed to be contained.
Also, this script doesn't work how it should. I mean it works, but the switch statement only delivers the last string that contains an error, and if I put it inside the foreach, it gives out 1 time the first error and 3 times the second error.
What am I doing wrong? Please help me!
<?php
// test variables
$act1 = "SUBSCRIBEa";
$act2 = "SUBSCRIBEb";
$act3 = "SUBSCRIBE";
$act4 = "SUBSCRIBE";
// set error false as default
$error = "false";
// check if variables are ready for use
if(!empty($act1) && !empty($act2) && !empty($act3) && !empty($act4)) {
$acts = [$act1, $act2, $act3, $act4];
// check the acts for lenght, numbers and special characters
// add all of the acts to an array to loop over
foreach($acts as $key => $value) {
if($key < 9) {
$errorKey = "0{$key}";
} else {
$errorKey = $key;
}
// check the lenght
if(strlen($value) > 15) {
$error = "true";
$errorNumber = $errorKey;
}
/* check for numbers and special characters
if(!preg_match('/[^a-z&A-Z]/', $value)){
$error = "true";
$errorNumber = $error_{$errorKey};
}
*/
// declare a whitelist of things that should not produce an error
$whiteList = [
'SUBSCRIBE',
'SUB & LIKE',
'LIKE & COMMENT',
'DISLIKE',
'COMMENT',
'LIKE',
'FOLLOW',
];
// check if value from act is in the whitelist declared above, if its not, set `$error` to true and set `$error_*` (with key) to "true" as well.
if(!in_array($value, $whiteList)) {
$error = "true";
$errorNumber = $errorKey;
}
}
}
// deliver the error message
switch($errorNumber){
case 00:
echo "Something went wrong here 1 :o";
break;
case 01:
echo "Something went wrong here 2 :o";
break;
case 02:
echo "Something went wrong here 3 :o";
break;
case 03:
echo "Something went wrong here 4 :o";
break;
}
?>

Answer 1

Try the following code, I commented as much as I could to try to show you what I did to (possibly) fix your issue.
<?php
// test variables
$act1 = "SUBSCRIBEa";
$act2 = "SUBSCRIBEb";
$act3 = "SUBSCRIBE";
$act4 = "SUBSCRIBE";
// set error false as default
$error = false;
// check if variables are ready for use, if they are, add them to `$acts` array
// I do each check as a seperate line, as it looks cleaner than 1 long if statement.
$acts = [];
if(!empty($act1)) $acts[] = $act1;
if(!empty($act2)) $acts[] = $act2;
if(!empty($act3)) $acts[] = $act3;
if(!empty($act4)) $acts[] = $act4;
// declare a whitelist (outside of loop) of things that should not produce an error
$whiteList = [
'SUBSCRIBE',
'SUB & LIKE',
'LIKE & COMMENT',
'DISLIKE',
'COMMENT',
'LIKE',
'FOLLOW',
];
//create an empty array to hold errors
$errors = [];
// check the acts for lenght, numbers and special characters
// add all of the acts to an array to loop over
foreach($acts as $key => $value) {
//1 line ternary is cleaner than if/else statetmnt
$errorKey = $key < 9? "0{$key}" : $key;
//each row by default has no error
$hasError = 0;
// check the lenght
//use regex to check if a string only contains letters.
// check if value from act is in the whitelist declared above, if its not, set `$error` to true and set `$error_*` (with key) to "true" as well.
// make sure you use `||` (or) here, not `&&` (and), otherwise this statement will not work properly. If it's `||` only 1 thing has to be wrong, if it's `&&` then all of them have to be wrong.
if(strlen($value) > 15 || preg_match('/[^A-Za-z &]/', $value) || !in_array($value, $whiteList)) {
$error = true;
//if error occurs, set `$hasError` to 1, to later insert errorKey into array.
$hasError = 1;
}
//
if($hasError) {
//store error in array, to loop through later
$errors[] = $errorKey;
}
}
// deliver the error message
//Check if $error has been set to true at any point
if($error) {
//loop through error array, echo error message if $errorNumber matches.
//at this point we KNOW there was an error at some point, no need to use a switch really
foreach($errors as $errorNumber) {
echo "Something went wrong here $errorNumber :o";
}
}
?>