objMapKeys

Returns a new object whose keys are the values returned by the callback. The values are carried over untouched.

The callback receives (value, key), in that order, matching the rest of the ecosystem, and must return a string. Only the top level is inspected — the keys of a nested object are left alone.

When two keys map onto the same name, the later one wins. The original object is not modified, and nullNone is returned when the first argument is not an object.

Parameters

Name	Type	Required	Default
obj	objectMap<String, dynamic>dict	●	–
The object whose keys are mapped. It is not modified.
iteratee	functionString Function(dynamic value, String key)Callable	●	–
Called as (value, key) for every entry. Its return value becomes the new key.

Returns

object | null

Map<String, dynamic>?

dict | None

Examples

objMapKeys({ a: 1, b: 2 }, (value, key) => key.toUpperCase()); // Returns { A: 1, B: 2 }
objMapKeys({ a: 1, b: 2 }, (value, key) => `${key}${value}`); // Returns { a1: 1, b2: 2 }
objMapKeys({ a: 1, b: 2 }, () => 'x'); // Returns { x: 2 }

objMapKeys({'a': 1, 'b': 2}, (value, key) => key.toUpperCase()); // Returns {'A': 1, 'B': 2}
objMapKeys({'a': 1, 'b': 2}, (value, key) => '$key$value'); // Returns {'a1': 1, 'b2': 2}
objMapKeys({'a': 1, 'b': 2}, (value, key) => 'x'); // Returns {'x': 2}

objMapKeys({'a': 1, 'b': 2}, lambda value, key: key.upper())  # Returns {'A': 1, 'B': 2}
objMapKeys({'a': 1, 'b': 2}, lambda value, key: f'{key}{value}')  # Returns {'a1': 1, 'b2': 2}
objMapKeys({'a': 1, 'b': 2}, lambda value, key: 'x')  # Returns {'x': 2}