JAVASCRIPT

create dropdown in flutter

DropdownButton(
  value: currentItem,
  items: items
      .map<DropdownMenuItem<String>>(
        (e) => DropdownMenuItem(
          value: e,
          child: Text(e),
        ),
      )
      .toList(),
  onChanged: (String? value) => setState(
    () {
      if (value != null) currentItem = value;
    },
  ),
),

Create DropDown List in Flutter: DropdownButton Widget

Center(
  child: Column(
    mainAxisAlignment: MainAxisAlignment.spaceEvenly,
    children: [
      DropdownButton(
        value: currentItem,
        items: items
            .map<DropdownMenuItem<String>>(
              (e) => DropdownMenuItem(
                value: e,
                child: Text(e),
              ),
            )
            .toList(),
        onChanged: (String? value) => setState(
          () {
            if (value != null) currentItem = value;
          },
        ),
      ),
      Text(currentItem),
    ],
  ),
)

dropdown item from the list flutter

  List<DropdownMenuItem<String>> getDropdownItems() {
    List<DropdownMenuItem<String>> dropDownItems = [];

    for (String currency in currenciesList) {
      var newDropdown = DropdownMenuItem(
        child: Text(currency),
        value: currency,
      );

      dropDownItems.add(newDropdown);
    }
    return dropDownItems;
  }