Maps (aka Hashes, Associative Arrays)
Key-value pairs are implemented in Dart by Map objects. Defining an options hash creates a Map.[4]
| primitives/hash_map.dart | |
| | var options = { |
| | 'color': 'red', |
| | 'number': 2 |
| | }; |
As you’d expect, retrieving values from a Map is done with square brackets.
| | options['number']; // 2 |
Map objects support the usual methods. This includes retrieving keys (the keys getter method) and values (the values getter) and iterating over the entire object with forEach.
| | var options = { |
| | 'color': 'red', |
| | 'number': 2 |
| | }; |
| | options.forEach((k, v) { |
| | print("$k: $v"); |
| | }); |
| | // number: 2 |
| | // color: red |
| Recipe 4 | The order of key-value pairs is not guaranteed in most classes that implement the Map interface (like ... |
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