easy one...i think

just trying to print the strings before and after then character replacement

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

 String reportString = "SensorReading: 456";
    Serial.print(reportString);
 
 int colonPosition = reportString.indexOf(':');
 reportString.setCharAt(colonPosition, '='); 
 
    Serial.print(reportString);

void loop() {
  // put your main code here, to run repeatedly:

}

error-report 04-14-20.txt (6.37 KB)

this

 String reportString = "SensorReading: 456";
    Serial.print(reportString);
 
 int colonPosition = reportString.indexOf(':');
 reportString.setCharAt(colonPosition, '='); 
 
    Serial.print(reportString);

is OUTSIDE setup() or loop(). they should be inside EITHER function.

like this:
(compiles not test)

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

  String reportString = "SensorReading: 456";
  Serial.print(reportString);

  int colonPosition = reportString.indexOf(':');
  reportString.setCharAt(colonPosition, '=');

  Serial.print(reportString);
}



void loop() {
  // put your main code here, to run repeatedly:

}

hope that helps
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