ASP.NET Core Interview Question #18

What is the Options pattern in ASP.NET Core?

ASP.NET Core Fundamentals Junior Beginner

Quick Interview Answer

The Options pattern binds related configuration values to a strongly typed class and makes them available through interfaces such as IOptions<T>, IOptionsSnapshot<T>, and IOptionsMonitor<T>.

Detailed Explanation

The Options pattern binds related configuration values to a strongly typed class and makes them available through interfaces such as IOptions<T>, IOptionsSnapshot<T>, and IOptionsMonitor<T>.

It avoids scattering string-based configuration keys throughout the application and makes settings easier to validate, test, and maintain.

IOptions<T> provides a value, IOptionsSnapshot<T> is useful for scoped/request-based refreshed options, and IOptionsMonitor<T> supports change notifications and current values for long-lived services.

Code Example

builder.Services.Configure<EmailOptions>(
    builder.Configuration.GetSection("Email"));

public class EmailOptions
{
    public string Host { get; set; } = string.Empty;
    public int Port { get; set; }
}