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Help me figure this out, I don't know what that line means in the code.

K
Kadir last edited by
```
var someVariable = someClassInstance?.CallMethod();
```
What is this sign of the question and how can it be applied in practice?
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A
Avante last edited by
?. - it's a new operator at C# 6.0. It is called null propagation operator (I don't know how Russian will be). This is...
```
var someVariable = someClassInstance?.CallMethod();
```
a short version of this code:
```
var someVariable = someClassInstance == null ? null : someClassInstance.CallMethod();
```
It also provides https://docs.microsoft.com/ru-ru/dotnet/csharp/language-reference/operators/member-access-operators#thread-safe-delegate-invocation ♪
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void create and T create<t></t>
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 Does the use of both is deagreement to the scenario I have, should I use one or the other?Depends on the purpose of each method, if it isFind() it would be quite rare to define it as void, as it is supposed to search and return the list of entitiesDelete() may not return anything, as you just have to removeأعربية أبية Русский أعامنامنامامامامامامان مامامامامامامامامامامامامان موامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامامانIt should not bring problems even if the instance of the entity framework context should be by request, that is, each transaction should create a new instanceIf you develop a web project the instance defines the request to the server. If it is a desktop development when you start a transaction generates the instance of the repository and it must be destroyed when it ends.
What does that line of code in java mean?
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EnumMap - That's it. HashMap Optimized by enum's use.After the line:EnumMap<Symbol, Object> commands = new EnumMap<Symbol, Object>(Symbol.class) There will be an empty hush table.If there's anything lying there, you'll have to add, for example:commands.put(STATE.FIRST_DIGIT, "I'm digit"); commands.put(STATE.SECOND_DIGIT, "I'm second digit"); commands.put(STATE. OPERATION, "I'm operation"); Transferring the type to the designer is necessary, as I said, the structure is optimized to use the enums. By transferring the key type to the designer, we allow the maximum number of elements in the table at an early stage (as the same keys cannot be present and the elements enum'a cannot be changed dynamically).
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... using UnityEngine; using UnityEngine.AI;
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Just take that Provider of the connection string. .connectionString="Server=SRVSQLDEALER\VDLSQLDB; User ID=monitor; Password=monitor; Database=dbRentabilidade_teste;Persist Security Info=True;"
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Got it. Helped by the following: var uri = decodeURIComponent(window.location.search) We're working with the variable. uri
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XOR uses the following characteristics: (a XOR k) XOR k = a where k is the keyYour program is encrypted in a sympathetic way: that is, it uses XOR to every symbol of the reference line. Discrypts it as quickly as possible using XOR and the same key again.
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How do you get an original URL picture orientation?
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I suspect the img tag can't recognize the vision.I suspect that TEG doesn't know anything in principle. Defines the browser, but does it depending on your content. When looking purely, it responds to orientation, and when used as part of the HTML page, it looks only at size.Search for / write polyfils for the browsers you need. Typically, the pictures are turned by special lips when they're downloaded to the server and they're already stored. Then there's little previews.Here's decision for a client's orientation: https://stackoverflow.com/questions/7584794/accessing-jpeg-exif-rotation-data-in-javascript-on-the-client-side
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You have an incorrect record of team sequence, to team up CREATE DATABASE testdb and only after the base has been established follow the following teamUSE testdb Little advice before you do SQL code C#Try to chase him. SQL Management Studio
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Try using the method. Number.isNaN(...) for verification NaNif (!Number.isNaN(myAge)) { alert("Wrong"); } I will also note that data from all inputs are returned in a structured format and should be listed. They usually do that: let myAge = +check.value;♪ But there are other ways.
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Observable<t>How to get out of T</t>
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Added (01/19)Oh... If you have any questions, the answer will change at all, so please update the answer.Observable The processing itself can be done asynchronously, so you need to wait for the end. As already mentioned, toBlocking() or BlockingObservable.from() HomeCode:public class ObservableTest { static class S3ObjectDummy { InputStream getObjectContent() { return new ByteArrayInputStream( "Arthur\nBob\nCharlie\nDick\nEdward".getBytes(StandardCharsets.UTF_8)); } } public static void main( String argv[]) { Observable<S3ObjectDummy> s3object = Observable.from( Arrays.asList(new S3ObjectDummy(), new S3ObjectDummy())); Observable<String> strObs = s3object.flatMap(obj -> Observable.<String>create((observer) -> { new Thread(() -> { try { BufferedReader reader = new BufferedReader(new InputStreamReader( obj.getObjectContent())); String line; while ((line = reader.readLine()) != null) { observer.onNext(line + "(processed)"); } } catch (Throwable e) { observer.onError(e); } observer.onCompleted(); }).start(); }) ).reduce((acc, x) -> acc + "\n" + x); // 完了を待つ BlockingObservable<String> blockObs = strObs.toBlocking(); // 取得 System.out.println( blockObs.first()); } } It’s so cute. The sample code, but the compile error is also. Thread I was a little worried about using it. I think that it was as follows.public class ObservableTest { static class S3ObjectDummy { InputStream getObjectContent() { return new ByteArrayInputStream( "Arthur\nBob\nCharlie\nDick\nEdward".getBytes(StandardCharsets.UTF_8)); } } public static void main( String argv[]) { Observable<S3ObjectDummy> s3object = Observable.from( Arrays.asList(new S3ObjectDummy(), new S3ObjectDummy())); s3object.flatMap(ObservableGet::processLines) .reduce((acc, x) -> acc + "\n" + x) .toBlocking() .forEach( System.out::println); } public static Observable<String> processLines( S3ObjectDummy obj) { return Observable.<String>create((observer) -> { try { BufferedReader reader = new BufferedReader(new InputStreamReader( obj.getObjectContent())); String line; while ((line = reader.readLine()) != null) { observer.onNext(line + "(processed)"); } } catch (Throwable e) { observer.onError(e); } observer.onCompleted(); }).subscribeOn(Schedulers.newThread()); } } Old Answers (01/18)Preparing質問 the sample code of the question.Observable<String> obs = Observable.from("hoge"); obs.subscribe((String str) -> { System.out.println(str); }); // => <compile error> Let's look cool.Observable.from(Arrays.asList("hoge").subscribe((s) -> System.out.println(s)); // Output: hoge to cancel an array,from Home just can be changed.Observable.just("hoge").subscribe((s) -> System.out.println(s)); // Output: hoge Separate linesObservable o = Observable.just("hoge"); o.subscribe((s) -> System.out.println(s)); // Output: hoge ...and get it from here.Observable.just() Know the movementjust() Objservable is used only inside. I'll do it to earn speed.System.out.println(ScalarSynchronousObservable.create("hoge").get()); // Output: hoge Directly hold observation targets Observable MakeHold the object to be observed in order to realize the question "How to get the Observable T" in the sample code baseObservableLet's make an implementation?class ObservableWithGet<T> extends Observable<T> { public static final <T> ObservableWithGet<T> create(T t) { return new ObservableWithGet<T>(t);　} private final T t; protected ObservableWithGet(final T t) { super((Subscriber<? super T> s) -> { s.onNext(t); s.onCompleted(); }); this.t = t; } public T get() { return t; } } I think you can realize what you want.ObservableWithGet o = ObservableWithGet.create("hoge"); System.out.println(o.get()); o.subscribe((s) -> System.out.println(s)); // Output: hoge\nhoge
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Decided by adding properties to the style..card-deck .card { margin: 0 1%; flex: 0 1 22%; }
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It is possible to do this using Any LINQ too.In VB.NETWith LINQDim existeMaiuscula As Boolean = senha.Any(Function(c) Char.IsUpper(c)) With RegexDim existeMaiuscula As Boolean = Regex.IsMatch(senha, "\p{Lu}") In C# With LINQvar existeMaiuscula = senha.Any(c => Char.IsUpper(c)); With Regexvar existeMaiuscula = Regex.IsMatch(senha, @"\p{Lu}");
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In functional programming, it is common to transfer another sentence to one sentence. The first sentence would, if necessary, call for the second sentence, most often with the transmission of parameters. In some languages, it's called "colleback."For example, we want to describe a phrase that prints out of the number, adds 10 to them, but only deals with the numbers that satisfy the condition that we will pass the trace.def select_and_add_10 array, condition array.each do |element| p element + 10 if condition.call element end end Here. condition - the variable through which the Lambdu is transferred to the use of the language select_and_add_10 Here we go.select_and_add_10 [1,2,3,4,5,6,7], lambda{ |element| 2 < element && element < 6 } 131415But not to write. lambdaRuby has syntax sugar called blocks.do end() -- the flaw is that the Lambad can be transferred as much as it is simply the arguments of the function and only one unit is transferred.def select_and_add_10 array, &condition array.each do |element| p element + 10 if condition.call element end end select_and_add_10 [1,2,3,4,5,6,7] do |element| 2 < element && element < 6 end And yield - it's another syntax sugar that doesn't name the block, because it's only one that doesn't need an ID.def select_and_add_10 array array.each do |element| p element + 10 if yield element end end select_and_add_10([1,2,3,4,5,6,7]) do |element| 2 < element && element < 6 end
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Since I didn't wait to answer my question, I had to write a bicycle like this.private void InitMapper() { var types = GetTypes(typeof(Parent)); foreach (var type in types) { CreateMap(type, type).ForAllMembers(options => options.UseDestinationValue() ); } } private static List<Type> GetTypes(Type type) { var list = new List<Type> { type }; var props = type.GetProperties(); foreach (var item in props) { var currentType = item.PropertyType.IsArray ? item.PropertyType.GetElementType() : item.PropertyType; if (currentType.IsPrimitive == false && currentType.IsClass && currentType != typeof(String)) { list.AddRange(GetTypes(currentType)); } } return list; }

Help me figure this out, I don't know what that line means in the code.

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