What is the meaning of name = name ?? data?.name;

Question

I am working with an HTTP triggered Azure Function and am new to it.

namespace FunctionApp2
{
    public static class Function1
    {
        [FunctionName("Function1")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

            string name = req.Query["name"];

            string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
            dynamic data = JsonConvert.DeserializeObject(requestBody);
            name = name ?? data?.name;

            string responseMessage = string.IsNullOrEmpty(name)
                ? "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response."
                : $"Hello, {name}. This HTTP triggered function executed successfully.";

            return new OkObjectResult(responseMessage);
        }
    }
}

I am not understanding line name = name ?? data?.name; What is it doing and why is there two ? marks. Also what is [FunctionName("Function1")] doing like what is the significance of two braces[].

Also see https://learn.microsoft.com/en-us/dotnet/csharp/tutorials/attributes — Matthew Watson, Jan 23 '23 at 09:39
And see https://learn.microsoft.com/en-us/azure/azure-functions/functions-dotnet-class-library?tabs=v4%2Ccmd#methods-recognized-as-functions — Matthew Watson, Jan 23 '23 at 09:40
data is the JSON object that contains name parameter with value passed in the runtime of the Azure Function. And the line `name = name ?? data?.name` is checking the value passed to name is valid string or null — , Jan 23 '23 at 09:55
Hello I am not properly understanding the ?. part. The links were helpful to understand ?? but still I am not undertanding ?. in name = name ?? data?.name — Alok Kumar, Jan 23 '23 at 10:03
null-coalescing operator (??) in C# returns the value based on the input sent to the parameters. If value is sent to the name parameters, then it returns "Hello, {name}. This HTTP triggered function executed successfully" in the Http Response. If you are not passing any value to the name parameter in the function URL, then you'll get the HTTP response like "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response."" — , Jan 23 '23 at 10:07
[`?.` is the null-conditional operator](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/member-access-operators#null-conditional-operators--and-) — Matthew Watson, Jan 23 '23 at 11:19

What is the meaning of name = name ?? data?.name;

0 Answers0