List object dart

Flutter Dart Convert Map to List & List to Map

In this post we are going to learn how to convert Map to List and List to Map in Dart/Flutter.

What is List in Dart?

Dart represents arrays in the form ofListobjects. AListis simply an ordered group of objects

List is classified in two ways

• Fixed Length List
• Growable List

What is Map?

The Map object is a simple key/value pair. Keys and values in a map may be of any type. A Map is a dynamic collection

Map can be classified as below

• Using Map Literals
• Using a Map constructor

Read dart list tutorial

Let's check

Suppose we have a class called User

Now let's convert List into Map and vice versa

Convert Map to List in Dart/Flutter

Let's initialize Map

We will convert thisMaptoListwithCustomer.namefrom a key andCustomer.agefrom a value.
Before that, initialize an empty list first

Using Map forEach[] method

Now we convert our Map to List above usingforEach[]method

In the code above, we create a newUserobject from each key-value pair, then add the object to the user_list.

Output:

Using Iterable forEach[] method

We can also convert a Dart Map to List using IterableforEach[]method instead.

Output:

Using Iterable map[] method

Another way to convert Map to a Dart List is to use Iterablemap[]method

Each entry item of Mapsentrieswill be mapped to a Userobject withentry.keyasuser.nameandentry.valueasuser.age.

Then we convert theIterableresult toListusingtoList[]method

Output:

Convert List to Map in Dart/Flutter

Now Let's create a List with User Info

Using Map.fromIterable[]

We convertListintoMapusingfromIterable[]constructor

Using Iterable forEach[] method

We can convert Dart List to Map in another way:forEach[]method

Compare list and maps using DeepCollectionEquality collection class

Conclusion: In this Dart tutorial we covered how to convert list to map and map to list in different ways

Read More

• Dart List class
• Dart Map class
• Dart Iterable class