String array problem

Projects Programming
1

Hi,

I have following piece of code:
jsonData is a json string.

String *getDepartures(String jsonData) {
  String departures[] = {jsonData.substring(49, 54), jsonData.substring(99, 104)};
  Serial.println(departures[0]);
  Serial.println(departures[1]);
  return departures;
}

the output here is e.g.
17:40
17:55
both as string. Then I try to return the data and check the output again.

void loop() {
  String *departures = getDepartures(runCurl());
  Serial.println(departures[0]);
}

The output here is then like
:40 but I aspected 17:40

I tried to understand the pointer stuff but ... :disappointed_relieved:
This part for me is clear. That is similar to PHP for me, or I'm completely wrong.

String departures[] = {jsonData.substring(49, 54), jsonData.substring(99, 104)};
Serial.println(departures[0]);
Serial.println(departures[1]);

Some thing on the return of the string is wrong.
small help would be great. Thanks.

2

The array that you are returning is local to the function. It goes out of scope when the function ends. You should NOT be returning a pointer to a local variable.

Pass the array to store the data to the function. No need to return anything.

3

huch, so easy, Thanks for that hint.