# duplicate_named_argument

> Details about the duplicate_named_argument diagnostic produced by the Dart analyzer.



_The argument for the named parameter '{0}' was already specified._

## Description

The analyzer produces this diagnostic when an invocation has two or more
named arguments that have the same name.

## Example

The following code produces this diagnostic because there are two arguments
with the name `a`:

```dart
void f(C c) {
  c.m(a: 0, [!a!]: 1);
}

class C {
  void m({int? a, int? b}) {}
}
```

## Common fixes

If one of the arguments should have a different name, then change the name:

```dart
void f(C c) {
  c.m(a: 0, b: 1);
}

class C {
  void m({int? a, int? b}) {}
}
```

If one of the arguments is wrong, then remove it:

```dart
void f(C c) {
  c.m(a: 1);
}

class C {
  void m({int? a, int? b}) {}
}
```

