Wrong argument type for Collection remove method JAVA-E1036
Bug risk
Major
5 months ago
—
a year old
Expected an argument of type Token, got Object instead
323 }
324 break;
325 case COMMA: // (2)
326 result.remove(lastIndex);327 break;
328 default:
329 break;Expected an argument of type Lexer, got Object instead
136 available.add(getLexer());
137 }
138 var instance = available.iterator().next();
139 available.remove(instance);140 inUse.add(instance);
141 return instance;
142 }
Description
Arguments to collection remove* methods must be of the same type as the collection itself.
Though Collection is parameterised on the type of the contained values, Collection.remove() is not; it accepts a parameter of type Object instead. This means any value can be passed to a collection's remove() method, regardless of whether the value's type matches the collection's type.
This is also exacerbated for lists that store integers; List has both an Object and an int overload for remove() that are easy to confuse.
Bad Practice
List<Integer> ints = Arrays.asList(3);
ints.remove("3"); // this will fail silently!
Recommended
Ensure that the type of the value passed to remove() is the same as the collection's type.
ints.remove((Object)3);
References
- Oracle Java 11 JavaDocs -
java.util.Collection