Dart Constants
Since the Dart Constant is specified as an immutable object, it cannot be altered while the program is running. It is not possible to change the value once it has been initialized to the constant variable.
Defining/Initializing Constant in Dart
There are two definitions for the Dart constant.
- Using the final keyword
- Using the const keyword
It is useful when we wish to maintain the value throughout the entire program. To construct a constant variable, use the terms final and const. The data-type is used in combination with the keywords final and const. If we attempt to change the constant variable, Dart will raise an exception.
The compile-time constant is represented by a const keyword, and the final variable can only be set once.
Define Constant Using final Keyword
The last term allows us to define the constant. Below is the syntax.
Syntax
final const_name;
or
final data_type const_name
Example
void main () {
final a = 10;
final b = 20;
print(a);
print(b);
}
Output
10
20
Define Constants Using const Keyword
The const keyword allows us to define constants. Below is the syntax.
Syntax
const const_name
Or
const data_type const_name
Example
void main() {
const name= "Peter";
print(name);
}
Output
Peter
