no_wildcard_variable_uses

The referenced identifier is a wildcard.

The analyzer produces this diagnostic when either a parameter or local variable whose name consists of only underscores is referenced. Such names will become non-binding in a future version of the Dart language, making the reference illegal.

The following code produces this diagnostic because the name of the parameter consists of two underscores:

// @dart = 3.6
void f(int __) {
  print(__);
}

The following code produces this diagnostic because the name of the local variable consists of a single underscore:

// @dart = 3.6
void f() {
  int _ = 0;
  print(_);
}

If the variable or parameter is intended to be referenced, then give it a name that has at least one non-underscore character:

void f(int p) {
  print(p);
}

If the variable or parameter is not intended to be referenced, then replace the reference with a different expression:

void f() {
  print(0);
}