Sets in Dart

Sets In Dart

Set is a unique collection of items. Duplicate items are not allowed in a set. Set is unordered so it can be faster than lists while working with large data. List allows you to add duplicate items but the set doesn’t allow duplicate items.

How To Create A Set

You can create set by using set type annotation like: Here Set<String> tells only Strings are allowed in the set.

void main(){
  Set<String> fruits = {"Apple", "Orange", "Mango"};
  print(fruits);
}

{Apple, Orange, Mango}

Check The Content

If you want to see set contain specific items or not, then you can use contains method, which returns true or false.

void main(){
  Set<String> fruits = {"Apple", "Orange", "Mango"};
  print(fruits.contains("Mango"));
  print(fruits.contains("Lemon"));
}

true
false

Add Items To Set

Like growable lists, you can add or remove items in a set. To add items use add() method and to remove items use remove() method.

void main(){
 Set<String> fruits = {"Apple", "Orange", "Mango"};
  
  fruits.add("Lemon");
  fruits.add("Grape");
  
  print("After Adding Lemon and Grape: $fruits");
  
  fruits.remove("Apple");
  print("After Removing Apple: $fruits");
}

After Adding Lemon and Grape: {Apple, Orange, Mango, Lemon, Grape}
After Removing Apple: {Orange, Mango, Lemon, Grape}

Adding Multipe Elements

You can use addAll method to add multiple elements from list to set.

void main(){
 Set<int> numbers = {10, 20, 30};
  numbers.addAll([40,50]);
 print("After adding 40 and 50: $numbers");
}    

After adding 40 and 50: {10, 20, 30, 40, 50}

Printing All Values In Set

You can print all items of set in dart by using for each loop or any other loop you want.

void main(){
 Set<String> fruits = {"Apple", "Orange", "Mango"};
  
 for(String fruit in fruits){
   print(fruit);
 }
}

Apple
Orange
Mango