Dart Variables and Data Types: Explained

Are you new to Dart programming language? Are you struggling to understand the concept of variables and data types in Dart? Fear not, because in this article, we will explain everything you need to know about Dart variables and data types.

What are Variables?

Variables are containers that store values in a program. In Dart, variables are declared using the var keyword followed by the variable name. For example, to declare a variable called name that stores a string value, you would write:

var name = "John";

In this example, the variable name is assigned the value "John". Dart is a dynamically typed language, which means that you don't have to specify the data type of a variable when you declare it. Dart will automatically infer the data type based on the value you assign to the variable.

Data Types in Dart

Dart has several built-in data types that you can use to declare variables. These data types include:

Numbers

Dart supports both integer and double-precision floating-point numbers. Integer numbers are declared using the int keyword, while double-precision floating-point numbers are declared using the double keyword. For example:

int age = 25;
double height = 1.75;

Strings

Strings are sequences of characters enclosed in quotation marks. Dart supports both single and double quotes for string literals. For example:

String name = "John";
String message = 'Hello, world!';

Booleans

Booleans represent true or false values. In Dart, booleans are declared using the bool keyword. For example:

bool isRaining = true;
bool isSunny = false;

Lists

Lists are ordered collections of objects. In Dart, lists are declared using square brackets []. For example:

List<int> numbers = [1, 2, 3, 4, 5];
List<String> names = ["John", "Mary", "Bob"];

In this example, we declare two lists: numbers and names. The numbers list contains integer values, while the names list contains string values. Note that we can specify the data type of the elements in a list by using angle brackets < >.

Maps

Maps are collections of key-value pairs. In Dart, maps are declared using curly braces {}. For example:

Map<String, int> ages = {"John": 25, "Mary": 30, "Bob": 35};

In this example, we declare a map called ages that maps string keys to integer values. The keys "John", "Mary", and "Bob" map to the values 25, 30, and 35, respectively.

Dynamic

The dynamic data type is a special data type in Dart that can hold any value. When you declare a variable as dynamic, Dart will not perform any type checks on the variable. For example:

dynamic value = 10;
value = "Hello, world!";

In this example, we declare a variable called value that is initially assigned an integer value of 10. Later, we assign a string value of "Hello, world!" to the same variable. Because value is declared as dynamic, Dart allows us to assign values of different data types to the same variable.

Type Inference

As we mentioned earlier, Dart is a dynamically typed language, which means that you don't have to specify the data type of a variable when you declare it. Dart will automatically infer the data type based on the value you assign to the variable. For example:

var age = 25;
var name = "John";

In this example, Dart infers that the variable age is an integer and the variable name is a string based on the values we assigned to them.

Conclusion

In this article, we explained everything you need to know about Dart variables and data types. We covered the different data types available in Dart, including numbers, strings, booleans, lists, maps, and dynamic. We also discussed type inference and how Dart automatically infers the data type of a variable based on the value you assign to it. We hope this article has helped you understand the concept of variables and data types in Dart. Happy coding!

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