We can use the isNotEmpty property of HashSet to confirm that a HashSet is not empty.
Note:
HashSetis an unordered,Hashtable-based set. You can read more aboutHashSethere.
bool isNotEmpty
This property returns True if the set contains at least one element. Otherwise, it returns False.
The code below demonstrates how to check if a HashSet is not empty.
import 'dart:collection';void main() {// create a new HashSetHashSet set = new HashSet();print("set is : $set");// check it the set is not emptyprint("Is set Not Empty : ${set.isNotEmpty}");// add elements to the setset.add(10);set.add(20);print("set is : $set");// check it the set is not emptyprint("Is set Not Empty : ${set.isNotEmpty}");}
Line 1: We import the collection library.
Line 4: We create a HashSet with the name set.
Line 8: We use the isNotEmpty property to check if set is empty or not. In this case, set does not contain any elements, so the property returns False.
Lines 11–12: We use the add() method to add two elements, 10 and 20, to the set.
Line 15: We use the isNotEmpty property to check if set is empty or not. Now, set contains two elements, so the property returns True.