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How to sort a Map by keys in Dart
Maria ElijahTo sort a Map, we can utilize the SplayTreeMap. Sorted keys are used to sort the SplayTreeMap.
A SplayTreeMap is a type of map that iterates keys in a sorted order. SplayTreeMap is a self-balancing binary tree. This means that frequently accessed items will be moved closer to the tree’s root.
Syntax
The following is the syntax to declare a SplayTreeMap:
SplayTreeMap map = SplayTreeMap();
Code
The following code shows how to sort a map by key:
import 'dart:collection';
void main() {
// Creating SplayTreeMap
var fruits = SplayTreeMap<int, String>();
// Adding key-value pairs
fruits[1] = 'Orange';
fruits[4] = 'Banana';
fruits[6] = 'Pawpaw';
fruits[3] = 'Apple';
fruits[5] = 'Mango';
fruits[2] = 'Avocado';
print("***Sorted map by keys**");
print(fruits);
// Iterating over map pairs using forEach method
fruits.forEach((key, val) {
print('{ key: $key, value: $val}');
});
}Using SplayTreeMap for sorting
In thecode above, we created a SplayTreeMap called fruits. By default, the keys are used to sort the pairs, which are sorted numerically and in ascending order.
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