Help with an error of sketch

Projects Programming
1

Hello,
given the approach of the exams and the problems with the initial project I was forced to change it in the hope of giving the commission examining something to see, but I found problems in the sketch, this sketch consists of 3 simple pieces that together form the distributor for animals (yes, I know this is not enough to take a good mark on the commission but I don't have time to prepare the machine I had in mind) the pieces are:
arduino
sensor
servo motor

the skerch is this:

#include <Servo.h>
#define trig 8
#define echo 9
int distanza;
int val;
Servo mioServo;
bool attivazione = false;
void setup() {
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);
Serial.begin(9600);
mioServo.attach (7);
}
void loop() {
digitalWrite(trig, LOW);
delay(10);
digitalWrite(trig, HIGH);
delay(10);
digitalWrite(trig, LOW);
distanza = pulseIn(echo, HIGH) / 58.2;
Serial.println(distanza);
delay(10);
if(attivazione == false && distanza >28)
{ attivazione = true;
for(val=0;val<55;val++)
{ Serial.println(val);
mioServo.write(val);
delay(1);
}
delay(50);
for(val=54;val>-1;val–)
{Serial.println(val);
mioServo.write(val);
delay(1);
}
}
if(distanza < 28)
{
for(val=0;val<55;val++)
{ Serial.println(val);
mioServo.write(val);
delay(1);
}
delay(50);
for(val=54;val>-1;val–)
{Serial.println(val);
mioServo.write(val);
delay(1);
}
delay(10800000);
}
}

once copied and pasted I get this problem (which I think is due to a missing library in the program [but
I do not know which]):

for(val=54;val>-1;val–)

by copying the red part that appears below [from the error message copy] tells me:

exit status 1
stray '\342' in program

[Arduino:1.8.5 (Windows 10), Scheda:"Arduino/Genuino Uno"

sketch_jun03a:31: error: stray '\342' in program

for(val=54;val>-1;val–)

^

sketch_jun03a:31: error: stray '\200' in program

sketch_jun03a:31: error: stray '\223' in program

sketch_jun03a:45: error: stray '\342' in program

for(val=54;val>-1;val–)

^

sketch_jun03a:45: error: stray '\200' in program

sketch_jun03a:45: error: stray '\223' in program

exit status 1
stray '\342' in program

Questo report potrebbe essere più ricco di informazioni abilitando l'opzione
"Mostra un output dettagliato durante la compilazione"
in "File -> Impostazioni"
]

I take the sketch from this website:

I hope in an answer, in short timescales given the approach of the exams and the mistakes that the old project that caused me a change in all programs, thank you in advance for the answers (positive or negative that are)

2

++ Is a common unary operator, pre or postfix
-- is also a common unary operator, pre or postfix.

  • is not a common postfix operator
3

Please use code tags (</> button on the toolbar) when you post code or warning/error messages. The reason is that the forum software can interpret parts of your code as markup, leading to confusion, wasted time, and a reduced chance for you to get help with your problem. This will also make it easier to read your code and to copy it to the IDE or editor. If your browser doesn't show the posting toolbar then you can just manually add the code tags:
[code]``[color=blue]// your code is here[/color]``[/code]
Using code tags and other important information is explained in the How to use this forum post. Please read it.

Please always do a Tools > Auto Format on your code before posting it. This will make it easier for you to spot bugs and make it easier for us to read. If you're using the Arduino Web Editor you will not have access to this useful tool but it's still unacceptable to post poorly formatted code. I recommend you to use the standard IDE instead.

Alterasia:
I take the sketch from this website:

https://creaconarduinosite.files.wordpress.com/2017/07/nuovo-documento-di-microsoft-word.pdf

The owner of that site had the genius idea to take plain text code then run it through Microsoft Word to convert to a PDF. Microsoft had the genius idea to change a regular hyphen character (AKA minus) to an "en dash" (octal UTF-8 encoding 0342 0200 0223). If you examine the error message there was a good clue:

Alterasia:

 for(val=54;val>-1;val–)

You see how there is the gibberish characters where you would expect a minus?

C++ doesn't recognize "en dash" as a valid operator. You need to replace the instances of "en dash" with a real minus.