How does this code "know how to escape special characters"? - php

Question

Hello Stack Overflow Experts. I found this post and the author states, "... function knows how to escape special characters". I am still learning and I'm having difficulty seeing where the actual "handling" of special characters takes place and how they are "handled." Could someone point me in the right direction? Thank you. Here is the listed code:
$dataArray = csvstring_to_array( file_get_contents('Address.csv'));
function csvstring_to_array($string, $separatorChar = ',', $enclosureChar = '"', $newlineChar = "\n") {
// #author: Klemen Nagode
$array = array();
$size = strlen($string);
$columnIndex = 0;
$rowIndex = 0;
$fieldValue="";
$isEnclosured = false;
for($i=0; $i<$size;$i++) {
$char = $string{$i};
$addChar = "";
if($isEnclosured) {
if($char==$enclosureChar) {
if($i+1<$size && $string{$i+1}==$enclosureChar){
// escaped char
$addChar=$char;
$i++; // dont check next char
}else{
$isEnclosured = false;
}
}else {
$addChar=$char;
}
}else {
if($char==$enclosureChar) {
$isEnclosured = true;
}else {
if($char==$separatorChar) {
$array[$rowIndex][$columnIndex] = $fieldValue;
$fieldValue="";
$columnIndex++;
}elseif($char==$newlineChar) {
echo $char;
$array[$rowIndex][$columnIndex] = $fieldValue;
$fieldValue="";
$columnIndex=0;
$rowIndex++;
}else {
$addChar=$char;
}
}
}
if($addChar!=""){
$fieldValue.=$addChar;
}
}
if($fieldValue) { // save last field
$array[$rowIndex][$columnIndex] = $fieldValue;
}
return $array;
}