This tutorial shows multiple ways to convert List to Map in Dart or flutter programming.
The List is a dynamic collection of objects in Dart. The map is a data structure to store key and value pairs.
Both are different types in Dart or Flutter, and We have to write a code to convert from one type into another.
How to convert List to Map in Dart or Flutter programming
List.asMap() method converts a list into map type with indexed keys. And the returned map is unmodified and non-editable.
Here is an example program
main() {
List wordsList = ['one', 'two', 'three'];
Map wordsMap = wordsList.asMap();
print(wordsMap); //{0: one, 1: two, 2: three}
var numberList = [3, 6, 2, 7, 51, 15, 4];
Map numbersMap = numberList.asMap();// {0: 3, 1: 6, 2: 2, 3: 7, 4: 51, 5: 4}
print(numbersMap);
}
How to convert Map to List in Dart or Flutter programming?
The map contains keys and values.
to convert to List, use toList() method.
map.keys
returns keys of type Iterable<dynamic>
and map.values
returns values of type Iterable<dynamic>
.
So call toList() method on returned keys and values to convert to List type.
map.keys.toList()
: converts keys into List of keys
map.keys.toList()
: method converts keys int List of values
Here is an example program to convert map key and values into separate lists
main() {
List wordsList = ['one', 'two', 'three'];
Map wordsMap = wordsList.asMap();
print(wordsMap); //{0: one, 1: two, 2: three}
var keyList = wordsMap.keys.toList();
print(keyList);
var valuesList = wordsMap.values.toList();
print(valuesList);
}
Conclusion
Learn How to Convert List to Map or Map to List in Dart or flutter programming.