Basic data question

Projects Programming
9

consider
bear in mind, an integer variable is being printed, not the received c-string

char s [80];

int val;

void loop() {
    if (Serial.available())  {
        int n = Serial.readBytesUntil ('\n', s, sizeof(s));
        s [n] = 0;

        val = atoi (s);
        Serial.println (val);
    }
}

void setup() {
    Serial.begin(9600);
}