String variable value is lost when get out from if branch.

[Larzu]

The following code is losing the string value when it's used outside of if-statement. Outside of if-statement the "original" variable payload is getting back the initial value x

esp8266/Arduino version 3.0.2
Board : LOLIN D1 mimi v.4.0.0

See the code and the output

#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <ESPAsyncWebServer.h>
#include <ESPAsyncTCP.h>
#include "LittleFS.h"
#include "time.h"

#include <ESP8266HTTPClient.h>
#include <WiFiClient.h>
#include <ArduinoJson.h>
---clip---

String httpsGETRequest(const char* serverName) {

String payload = "x"; 
String payload1 = "y"; 

 std::unique_ptr<BearSSL::WiFiClientSecure>client(new BearSSL::WiFiClientSecure);

client->setFingerprint(fingerprint);
// Or, if you happy to ignore the SSL certificate, then use the following line instead:
client->setInsecure();   
HTTPClient https;

Serial.print("[HTTPS] begin...\n");
if (https.begin(*client, serverName)) {  // HTTPS

  Serial.print("[HTTPS] GET...\n");
  // start connection and send HTTP header
  int httpCode = https.GET();

  // httpCode will be negative on error
  if (httpCode > 0) {
    // HTTP header has been send and Server response header has been handled
    Serial.printf("[HTTPS] GET... code: %d\n", httpCode);

    // file found at server
    if (httpCode == HTTP_CODE_OK || httpCode == HTTP_CODE_MOVED_PERMANENTLY) {
      Serial.println("getting payload");
      String payload = https.getString();
      payload1=payload;
      Serial.print ("PRINT payload (inside-if):  ");
      Serial.println(payload);
      payload1=payload;
      Serial.print ("PRINT payload1 (inside-if):  ");
      Serial.println(payload1);**

    }
  } else {
    Serial.printf("[HTTPS] GET... failed, error: %s\n", https.errorToString(httpCode).c_str());
  }
  Serial.print ("PRINT payload (outside-if):  ");
  Serial.println(payload);
  Serial.print ("PRINT payload1 (outside-if):  ");
  Serial.print("print payload1");
  Serial.println(payload1);
  https.end();

  return payload;
} else {
  Serial.printf("[HTTPS] Unable to connect\n");
}

}

[HTTPS] begin...
[HTTPS] GET...
[HTTPS] GET... code: 200
getting payload
PRINT payload (inside-if): {"0":{"time":"2022-12-19 13:00:00","value":"27.36"},"1"-----clip-----
PRINT payload1 (inside-if): {"0":{"time":"2022-12-19 13:00:00","value":"27.36"},"1"-----clip-----

PRINT payload (outside-if): x
PRINT payload1 (outside-if): print payload1{"0":{"time":"2022-12-19 13:00:00","value":"27.36"},"1"{-----clip---

[mcspr]

Not specific to esp8266, check out what variable scopes are
https://en.cppreference.com/w/cpp/language/scope

payload outside of if and inside of it are not the same

[Pablo2048]

The bug is exactly here:

    if (httpCode == HTTP_CODE_OK || httpCode == HTTP_CODE_MOVED_PERMANENTLY) {
      Serial.println("getting payload");
     >>> String payload = https.getString(); <<<

String payload =... create local variable with same name...