How to: Convert Future String to String vice versa in Dart| Flutter

This tutorial shows, how to Convert Future<String> to String in Dart and Flutter programming.

Convert Future String to String in Dart and Flutter

Asynchronous programming is supported through the async and await keywords in Dart and Flutter.

When retrieving data from the backend, data loads it asynchronously before displaying it in the front end. Future class uses for asynchronous operations in the Dart application.

It stores the various types of values returned by async operations. Its value is always a future value that awaits the completion of the function. The status of future value is both incomplete and completed.

  • Completed results in either success or error.
  • incomplete is an uncompleted future and waits for execution to finish.

Future<String> denotes that the Async API returns a future String value.

The string is a type used to store a group of characters. We have to convert from one type to another manually.

How do you convert Future String to Str in flutter?

dart:async package provides classes for async and awaits operations.

In the below example Created async function and converted a Future String using Future.value(). In real-time, this gets the data from the database. The Async function always returns Future Values.

Future.value(),takes input String value of dynamic type and return Future<String> values.


 Future<dynamic> Future.value([FutureOr<dynamic>? value])

Call the future String using await function that returns String.

Here is a code:

import 'dart:async';

void main() async {
  Future<String> stringFuture = _getMockData();
  String message = await stringFuture;
  print(message); // will print one on console.

Future<String> _getMockData() async{
  return Future.value("one");

The above example

  • Since _getMockData is marked as an async method, It returns Future, and tells String value in the future, this method does not wait for execution but executes in asynchronous execution.
  • awaits of this method returns value. awaits keyword waits for response returned from a method

How do you convert String to Future in flutter?

This example parses Future<String> into String values.

The string variable is created and assigned with the string literal. Next, Future class has a Future.value() method that creates a future value

Here is an example

import 'dart:async';

void main() async {
  String message = "Two";
  var futureValues = Future.value(message);
  print(futureValues); //Instance of '_Future<String>'
  print(futureValues.runtimeType); //_Future<String>


To summarize, We can easily convert String to Future<String> and Future<String> to String with examples.

Join 6,000 subscribers and get a daily digest of full stack tutorials delivered to your inbox directly.No spam ever. Unsubscribe any time.

Similar Posts
You'll get a notification every time a post gets published here.

Related posts

How to iterate loop Enum in Dart | Get Enum with index in Flutter By Example

Dart Enum comparison operator| Enum compareByIndex example| Flutter By Example

Dart tutorial examples/ Flutter By Examples

How to add Methods or Values to Enums in Dart | Flutter By Example

How to convert Double to Integer or Integer to double in Dart| Flutter By Example

How to: Enum to String in Dart | Print Enum name as String in Flutter By Example

Dart| Flutter How to get File name and extension with example