change an if / else if statement to a switch case in Arduino - server

Question

I am making a web server with an ESP32D, I am programming it from the Arduino IDE and I have a function with spaghetti code which I want to refactor with switch case,
this is my function, which i am calling in the void loop()
void control(){
if (header.indexOf("GET /2/on") >= 0) {
Serial.println("GPIO 2 on");
output2State = "on";
digitalWrite(output2, HIGH);
} else if (header.indexOf("GET /2/off") >= 0) {
Serial.println("GPIO 2 off");
output2State = "off";
digitalWrite(output2, LOW);
} else if (header.indexOf("GET /15/on") >= 0) {
Serial.println("GPIO 15 on");
output15State = "on";
digitalWrite(output15, HIGH);
} else if (header.indexOf("GET /15/off") >= 0) {
Serial.println("GPIO 15 off");
output15State = "off";
digitalWrite(output15, LOW);
}
}
void function_loop(){
WiFiClient client = server.available(); // Listen for incoming client
// Serial.println(typeOf(client));
if (client) { // If a new client connects,
currentTime = millis();
previousTime = currentTime;
Serial.println("New Client."); // print a message out in the serial port
String currentLine = ""; // make a String to hold incoming data from the client
while (client.connected() && currentTime - previousTime <= timeoutTime) { // loop while the client's connected
currentTime = millis();
if (client.available()) { // if there's bytes to read from the client,
char c = client.read(); // read a byte, then
Serial.write(c); // print it out the serial monitor
header += c;
if (c == '\n') { // if the byte is a newline character
// if the current line is blank, you got two newline characters in a row.
// that's the end of the client HTTP request, so send a response:
if (currentLine.length() == 0) {
// HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
// and a content-type so the client knows what's coming, then a blank line:
client.println("HTTP/1.1 200 OK");
client.println("Content-type:text/html");
client.println("Connection: close");
client.println();
control();
}
How could I do to be able to pass it to switch case? I have no idea how to pass the variable to modify (in this case the header.indexOf)

Answer 1

It isn't clear from your example what type your header is, but I'm guessing it is a String.
Send header to control() like this
control(header);
and declare control() like this
void control(String& header) {