void setup() {
 for(X=1;x,<12;x++ ){ 

pinMode(x,);
}
}
void loop() {
 for(int x=12;x>=13;x++){

digitalWrite(x, HIGH);
delay(40);
digitalWrite(x, LOW);
delay(40);

}

 for(X=12;x>=1;x--){

digitalWrite(x, HIGH);
delay(40);
digitalWrite(x, LOW);
delay(40);
}
}
 
**Project Link:** https://wokwi.com/projects/385457772976602113?gh=1

Error message: sketch.ino: In function 'void setup()':
sketch.ino:7:6: error: 'X' was not declared in this scope
  for(X=1;x,<12;x++ ){
      ^
sketch.ino:7:6: note: suggested alternative: 'XH'
  for(X=1;x,<12;x++ ){
      ^
      XH
sketch.ino:7:10: error: 'x' was not declared in this scope
  for(X=1;x,<12;x++ ){
          ^
sketch.ino:7:12: error: expected primary-expression before '<' token
  for(X=1;x,<12;x++ ){
            ^
sketch.ino:9:11: error: expected primary-expression before ')' token
 pinMode(x,);
           ^
sketch.ino: In function 'void loop()':
sketch.ino:22:6: error: 'X' was not declared in this scope
  for(X=12;x>=1;x--){
      ^
sketch.ino:22:6: note: suggested alternative: 'XH'
  for(X=12;x>=1;x--){
      ^
      XH
sketch.ino:22:11: error: 'x' was not declared in this scope
  for(X=12;x>=1;x--){
           ^

Error during build: exit status 1