Objects and Classes
TS Interfaces
Defining Interfaces
TypeScript interfaces define object shapes supporting optional fields.
Introduction to TypeScript Interfaces
In TypeScript, interfaces are used to define the structure of an object. They act as a contract within your code, ensuring that objects adhere to a specific shape. This can help prevent runtime errors and improve the readability and maintainability of your code.
Defining an Interface
To define an interface in TypeScript, use the interface keyword followed by the name of the interface. The properties and their types are listed within curly braces. Here's a simple example:
Optional Properties
TypeScript interfaces also support optional fields. These are properties that may or may not be present within an object. To define an optional property, append a question mark ? after the property name:
Readonly Properties
Interfaces can also define readonly properties. These properties can only be assigned a value once and cannot be modified thereafter. To define a readonly property, use the readonly modifier:
Extending Interfaces
TypeScript interfaces can be extended, allowing you to build on existing interfaces. This is useful for creating complex types by combining simpler ones. Use the extends keyword to extend an interface:
Implementing Interfaces
Classes in TypeScript can implement interfaces, ensuring that they adhere to a specified shape. Use the implements keyword within a class to implement an interface:
Conclusion
TypeScript interfaces are a powerful feature that help define object shapes, ensure consistency across your codebase, and improve maintainability. By understanding how to use interfaces effectively, you can leverage TypeScript's type system to create robust applications.
