Map in Dart
Map is an object that consists of a key and a value.
- In Map , key must be of type String and value can be dynamic.
There are two ways to declare a map
- Map Literal
- Map Constructor
Map Literal
- With the Map Literal, you need to use a pair of curly brackets . Here’s an example of the syntax.
var names = { key1 : value1, key2 : value2 }
In Above Code there are key1 and key2 as keys in the map, and while value1 and value2 as the value of the keyword map.
void main() { var appName = {'name': 'Blog App', 'platform': 'Flutter-Android'}; print(appName); }
{name: Blog App, platform: Flutter-Android}
Dart Map Example
You Can Specific key,Use the following syntax
void main() { var appName = {'name': 'Blog App', 'platform': 'Flutter-Android'}; print(appName['name']); }
Blog App
Dart Maps
Constructor
It takes two steps to construct map, namely declaring and Initializing.
var name = new Map() name[key]=value
In Above Code , we initializing the map variable and adding map elements.
void main() { var appName = new Map(); appName['name'] = 'News App'; appName['platform'] = 'Flutter-Windows'; print(appName); }
flutter map
Various properties have been provided with Dart Map.
- keys – Returns all keys
- values – Returns all values
- length – Returns the length on the Map
- isEmpty – Returns true if the map element is empty, false otherwise
- isNotEmpty – Returns true if the map element is not empty. false otherwise.
void main() { var appName = new Map(); appName['name'] = 'News App'; appName['platform'] = 'Flutter-Windows'; appName['search'] = true; }
print(appName.keys); print(appName.values); print(appName.isEmpty); print(appName.isNotEmpty); print(appName.length);
The OutPut of above code
(name, platform, search) (News App, Flutter-Windows, true) false true 3