You've got way more errors showing than just the stray \342.
Read the answer above yours. Also read:
"You are using a Zero Width Non Joiner character after the >> in your code. This is a unicode character that is encoded in UTF-8 as three characters with values 0x2e, 0x80, 0x8c (or in base 8, \342, \200, \214). This probably happened because you copy and pasted some code from a document (html web page?) that uses those special characters."
Here's what my IDE said re errors:
Arduino: 1.8.8 (Windows 10), Board: "Arduino MKR WiFi 1010"
sketch_dec30c:1:1: error: stray '\342' in program
int​ ledCount = 14; int​ ledPins[] = { 6, 7, 8, 9, 10, 11, 12, 13, 12, 11, 10, 9, 8, 7 }; int​ ledDelay = 300; int​ buttonPin = 2;
^
sketch_dec30c:1:1: error: stray '\200' in program
sketch_dec30c:1:1: error: stray '\213' in program
sketch_dec30c:1:1: error: stray '\342' in program
sketch_dec30c:1:1: error: stray '\200' in program
sketch_dec30c:1:1: error: stray '\213' in program
sketch_dec30c:1:1: error: stray '\342' in program
sketch_dec30c:1:1: error: stray '\200' in program
sketch_dec30c:1:1: error: stray '\213' in program
sketch_dec30c:1:1: error: stray '\342' in program
sketch_dec30c:1:1: error: stray '\200' in program
sketch_dec30c:1:1: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
void​ ​setup​() { ​for​ (​int​ thisLed = 0; thisLed < ledCount; thisLed++) { ​pinMode​(ledPins[thisLed], ​OUTPUT​); } pinMode​(buttonPin, ​INPUT​); }
^
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:2:2: error: stray '\342' in program
sketch_dec30c:2:2: error: stray '\200' in program
sketch_dec30c:2:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
void​ ​loop​() { ​for​ (​int​ thisLed = 0; thisLed < ledCount-1; thisLed++) { ​digitalWrite​(ledPins[thisLed], ​HIGH​); ​delay​(ledDelay); ​while​(​digitalRead​(buttonPin) == ​HIGH​) { ​delay​(10); } ​digitalWrite​(ledPins[thisLed], ​LOW​); } }
^
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
sketch_dec30c:3:2: error: stray '\342' in program
sketch_dec30c:3:2: error: stray '\200' in program
sketch_dec30c:3:2: error: stray '\213' in program
exit status 1
stray '\342' in program
This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.
You can see all sorts of shit like:
"void​ ​loop​()"
Assuming this is copy-pasted, try cleaning up the code...