What are data annotations in ASP.NET validation?

What are data annotations in ASP.NET validation?

Data annotations are attributes used in ASP.NET to specify validation rules for model properties.

Can you give me some examples of data annotations?

Sure! Common examples include [Required], [StringLength], and [Range]. They help enforce rules on user input.

How do I implement these annotations in my model?

You simply add the desired annotation above the property in your model class. For example:

public class User {
    [Required]
    public string Name { get; set; }
}

What happens if validation fails?

If validation fails, the model state will be invalid, and you can return error messages to the user.