Dart dynamic variable

Let’s learn about the Dart dynamic variable in this tutorial. The var data type will replace the appropriate data type of the variable when a value is assigned to the variable.

Steps to create Dart new project in IntelliJ IDE:

https://www.testingdocs.com/new-dart-project-using-intellij-ide/

Dart dynamic variable

The Dart programming language supports a special variable type called dynamic data type. Dart provides the dynamic type, which allows a variable to hold values of any data type. The data type of a dynamic variable is resolved at runtime. When a variable is declared as dynamic, the variable can store any value during runtime without a specific data type.

Example

Let’s see how the dynamic keyword works. The datatype dynamically changes when we assign different data to the dynamic variable in the program.

/*
 Dynamic variables Demo Program
 Dart Tutorials - www.TestingDocs.com
 */

void main()
{
  // Store a String
  dynamic foo = "TestingDocs.com";

  // print the value of the variable
  print("Before : $foo");

  // Let's reassign a number integer data type to the variable
  foo = 2016;

  // print the value
  print("After  : $foo");
}

The foo variable is the dynamic variable. The foo variable can dynamically store any data type during runtime.

We assigned a string data and later reassigned an integer number to the same variable.

Output

Before : TestingDocs.com
After : 2016

The difference between dynamic and var datatype in Dart is that the var will replace itself with the appropriate data type when assigning a value to the variable. If the foo variable is declared with the var keyword assigned a string data, and then later we cannot assign another data type to the variable.