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

Map - Dart Programming

Map in Dart

Dart Map Example

Dart Maps

flutter map