yostane

func handleNilWithoutGuardMethod1(str: String?){
    if str == nil {
        print("str is nil")
        return
    }
    let s = str!
    print("s in not nill here \(s)")
    //do other things here
}

yostane

func handleNilWithoutGuardMethod2(str: String?){
    if let s = str {
        print("s in not nil here \(s)")
        //do other things here
    }else{
        print("str is nil")
    }
}
handleNilWithoutGuardMethod2(str: nil)
handleNilWithoutGuardMethod2(str: "hello")

yostane

func guardMe(str: String?){
    guard let s = str else{
        print("str is nil")
        return
    }
    print("s in not nil here \(s)")
    //do other things here
}

guardMe(str: nil)

yostane

func guardMe2(str: String?){
    guard let s = str, s == "hello" else{
        print("str is nil or not equal to hello")
        return
    }
    print("s is equal to hello \(s)")
    //do other things here
}

guardMe2(str: nil)

yostane

while (mySerial.available()) {
  Serial.write(mySerial.read());
}

yostane

void sendCommand(const char * command){
  Serial.print("Command send :");
  Serial.println(command);
  mySerial.println(command);
  //wait some time
  delay(100);
  
  char reply[100];
  int i = 0;
  while (mySerial.available()) {

yostane

void setup() {
  // put your setup code here, to run once:
  mySerial.begin(9600);
  Serial.begin(9600);

  sendCommand("AT");
  sendCommand("AT+ROLE0");
  sendCommand("AT+UUID0xFFE0");
  sendCommand("AT+CHAR0xFFE1");
  sendCommand("AT+NAMEbluino");

yostane

void readSerial(){
  char reply[50];
  int i = 0;
  while (mySerial.available()) {
    reply[i] = mySerial.read();
    i += 1;
  }
  //end the string
  reply[i] = '\0';
  if(strlen(reply) > 0){

yostane

void loop() {
  readSerial();
  delay(500);
}

yostane

void writeToBLE(char value) {
  Serial.print("Writing hex :");
  Serial.println(value, HEX);
  mySerial.write(value);
}