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

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

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

When retrieving data from the backend, data load it asynchronously before displaying it in the frontend. 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.

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. Async function always returns Future Values.

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

Syntax:

 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() {
  return Future.value("one");
}

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>
}

Conclusion

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