从Dart Map中删除选定的键

Question

从地图中删除选定键的Dart惯用方法是什么？下面我使用临时emptyList来保存String键.有更干净的方式吗？

List<String> emptyList = new List<String>();
_objTable.keys.forEach((String name) { 
  if (_objTable[name].indices.isEmpty) {
    emptyList.add(name);
    print("OBJ: deleting empty object=$name loaded from url=$url");
  } 
});
emptyList.forEach((String name) => _objTable.remove(name));

Answer 1

简单地做：

_objTable.removeWhere((key, value) => key == "propertyName");

它也适用于嵌套地图。

Answer 2

You can do something like this :

_objTable.keys
  .where((k) => _objTable[k].indices.isEmpty) // filter keys
  .toList() // create a copy to avoid concurrent modifications
  .forEach(_objTable.remove); // remove selected keys