Compare two boolean in Arduino

Using Arduino Programming Questions
#1

In my program, I need my Arduino to run a function when one boolean is not equal to another, I try to use if(streaming_switch!=in), but I get an error report:

       if(streaming_switch!=in)

          ~~~~~~~~~~~~~~~~^~~~

sketch\PCIO.h:186:26: note: candidate: operator!=(int, int) <built-in>

sketch\PCIO.h:186:26: note: candidate: operator!=(int, unsigned int) <built-in>

sketch\PCIO.h:186:26: note: candidate: operator!=(int, long int) <built-in>

sketch\PCIO.h:186:26: note: candidate: operator!=(int, long unsigned int) <built-in>

sketch\PCIO.h:186:26: note: candidate: operator!=(int, float) <built-in>

sketch\PCIO.h:186:26: note: candidate: operator!=(int, double) <built-in>

It seems that != operator cannot be used to compare boolean variables in Arduino.
Is there any alternative method to get the “not equal” condition between two boolean values?

#2

Don’t post snippets (Snippets R Us!)

can we really see the type of streaming_switch and in

this compiles and works fine

bool in, streaming_switch;

void setup() {
  Serial.begin(115200);
  in = true;
}

void loop() {
  streaming_switch = (random(0, 10) > 5);
  if (in != streaming_switch)
    Serial.println("different");
  else
    Serial.println("same");
  delay(1000);
}
#3

Thank you very much. "in"is a variable reading from a library and its definition is not clear in my program. It works after I replace it by if(streaming_switch!= (bool)in).

#4

I’m sure that we can find the type if you share the library information

casting to bool might not be what you want

#5

Thank you for your help. It is now working as I expect.
The library is called ThingerWiFiNINA.h, which is used to connect the device to a commercial server. From the introduction on their website, “in” should be a boolean value. But it may cast to double as all the variables are casting to double before transmission. Therefore, it should be fine if I just cast it back to bool.

#6

glad it works but it still does not make sense:
a boolean converted to a double will still be worth 0 or 1, so when you do the comparison with a boolean, the boolean is promoted to 0 or 1 which will match the double value (0 and 1 are precise in double format)
may be it’s not a bool but an enum and 0 is ‘false’ and you have multiple other values possible that are non 0
in that case comparing true and say 7 won’t indeed work unless you cast 7 back to a bool (which the spec says will be true if non null)

#7

I can’t find the definition of “in” from the library, but they also have similar commands like:
in = (bool) digitalRead(pin);
Casting a number to boolean will get true if the number is non-zero and false if the number is zero. They might just send 1 to my arduino if I select true on the server.

#8

OK

it’s not great coding as they rely on HIGH and LOW to be 1 and 0

in = (digitalRead(pin) == HIGH) ;

would be better