in Technology by
What is Fit and finish features in C#.Net?

1 Answer

0 votes
by

Many of the other features help you write code more efficiently. In C# 9.0, you can omit the type in a new expression when the created object's type is already known. The most common use is in field declarations:

private List<WeatherObservation> _observations = new();

Target-typed new can also be used when you need to create a new object to pass as an argument to a method. Consider a ForecastFor() method with the following signature:

public WeatherForecast ForecastFor(DateTime forecastDate, WeatherForecastOptions options)

You could call it as follows:

var forecast = station.ForecastFor(DateTime.Now.AddDays(2), new());

Another nice use for this feature is to combine it with init only properties to initialize a new object:

WeatherStation station = new() { Location = "Seattle, WA" };

You can return an instance created by the default constructor using a return new(); statement.

A similar feature improves the target type resolution of conditional expressions. With this change, the two expressions need not have an implicit conversion from one to the other, but may both have implicit conversions to a target type. You likely won’t notice this change. What you will notice is that some conditional expressions that previously required casts or wouldn’t compile now just work.

Starting in C# 9.0, you can add the static modifier to lambda expressions or anonymous methods. Static lambda expressions are analogous to the static local functions: a static lambda or anonymous method can't capture local variables or instance state. The static modifier prevents accidentally capturing other variables.

Covariant return types provide flexibility for the return types of override methods. An override method can return a type derived from the return type of the overridden base method. This can be useful for records and for other types that support virtual clone or factory methods.

In addition, the foreach loop will recognize and use an extension method GetEnumerator that otherwise satisfies the foreach pattern. This change means foreach is consistent with other pattern-based constructions such as the async pattern, and pattern-based deconstruction. In practice, this change means you can add foreach support to any type. You should limit its use to when enumerating an object makes sense in your design.

Next, you can use discards as parameters to lambda expressions. This convenience enables you to avoid naming the argument, and the compiler may avoid using it. You use the _ for any argument. For more information, see the Input parameters of a lambda expression section of the Lambda expressions article.

Finally, you can now apply attributes to local functions. For example, you can apply nullable attribute annotations to local functions.

Related questions

0 votes
    I have an activity A that launches B with an Intent. (B is a MapActivity and has some async code ... JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)...
asked Feb 18, 2022 in Education by JackTerrance
0 votes
    I created an LSTM with Keras API. Now I am facing an issue while I try to test different values ... JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)...
asked May 26, 2022 in Education by JackTerrance
0 votes
    I'd like to add a CMS and blog to a web app. One that won't get in the way. There's ... questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)...
asked Feb 28, 2022 in Education by JackTerrance
0 votes
    I am creating an UITableView using auto layout and prototype cells. I would like it to act more like ... Questions for Interview, JavaScript MCQ (Multiple Choice Questions)...
asked May 4, 2022 in Education by JackTerrance
0 votes
    I have a 9-cell grid containing images (using bootstrap columns). The grid works fine and is responsive ... Questions for Interview, JavaScript MCQ (Multiple Choice Questions)...
asked Apr 26, 2022 in Education by JackTerrance
0 votes
    I am currently using numpy.polyfit(x,y,deg) to fit a polynomial to experimental data. I would however ... Questions for Interview, JavaScript MCQ (Multiple Choice Questions)...
asked Feb 26, 2022 in Education by JackTerrance
0 votes
    ________ makes it incredibly easy to fit time series models like ARIMA, ARMA, AR, Exponential Smoothing, etc. (a ... of R Programming Select the correct answer from above options...
asked Feb 12, 2022 in Education by JackTerrance
0 votes
    In practice, Line of best fit or regression line is found when _____________ (a) Sum of residuals (∑(Y ... Regression of R Programming Select the correct answer from above options...
asked Feb 9, 2022 in Education by JackTerrance
0 votes
    To fit a graphic or clip art on to a slide you can change the (a) Design template (b) Slide layout (c) Colour scheme (d) Outline Select the correct answer from above options...
asked Dec 11, 2021 in Education by JackTerrance
0 votes
    Complete the sentence by choosing TWO WORDS either of which will fit the blank. The two words must both produce a ... on his bike. Select the correct answer from above options...
asked Nov 27, 2021 in Education by JackTerrance
0 votes
    A couple has two children. Find the probability that both are boys, fit is known that (a) one of the children is ... child is a boy. Select the correct answer from above options...
asked Nov 25, 2021 in Education by JackTerrance
0 votes
    R square value close to zero indicates a good fit. State if it is true or false? (1)True (2)False...
asked Aug 17, 2021 by JackTerrance
0 votes
    What is Garbage Collection in C#.Net?...
asked Jul 27, 2021 in Technology by JackTerrance
0 votes
    What is Reflection in C#.Net?...
asked Jul 27, 2021 in Technology by JackTerrance
...