Most voted "nullable" questions
Nullable, in programming, means that the variable will accept (in addition to the generally accepted types), the type NULL.
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answer745
viewsWhat is the usefulness of the exclamation (non null assertion Operator) in Typescript?
I recently discovered that in Typescript we can use the operator of non null assertion simply putting a ! where you want to check. When I saw it, I thought it was like in C#, that we have the ?,…
javascript typescript characteristic-language operators nullableasked 5 years, 4 months ago Francisco 7,472 -
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answers146
viewsIs there a disadvantage or is it harmful to use null types?
I always have trouble receiving null values from the database because I forget to use the cancellable types and face the same problem: The type cannot be null This usually happens with attributes…
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answers1349
viewsHow to convert a nullable int to common int
I have a method that gets an integer that can be null, if it happens some executions of methods, but when I will use the same variable in a place that uses int which cannot be null, it appears that…
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answer107
viewsCondition to check null variables does not work
I’m developing a page ASP (Classic) and on that page I have this: <%if(textocontrato) = "NULL" Then%> <td >Texto Contrato</td> <td ><input type="text" name="textocontrato"…
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answer332
viewsDelphi class with optional full-type field
The question is: how should I build my TPESSOA class so that the _id_city field can be null. Database Create Table PESSOA ( ID INTEGER NOT NULL, NOME VARCHAR(100) NOT NULL, ID_CIDADE INTEGER) No…
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answers2748
viewsPassing parameter null to a method
It is possible to pass/receive null parameters in Java. In C# I know it is possible using ? in kind. public DateTime Teste(DateTime? exemplo){...} In this case the example I know can come null, in…
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answer1533
viewsCompiler error or code error?
I came across the following case and do not know if it is . NET error or error in my implementation, same syntax (see image below). condenacaoInsert.qtd_ano_pena = null;…
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answer112
viewsIsGenericType, GetGenericTypeDefinition e Nullable.GetUnderlyingType
In a code snippet I was suggested the use of these three members in order to verify if the properties of an object are Nullable. p.PropertyType.IsGenericType &&…
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answer17
viewsError in Maproute configuration
The following error is returned to me: The Parameters Dictionary contains a null entry for Parameter 'numerodeserie' of non-nullable type 'System.Int32' for method 'System.Web.Mvc.Actionresult…
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answer27
viewsSelect with Null Field
I’m doing a survey in a student database, and I started having the following problem: Every time a student fails to fill in the "address" field, even though he has all the other data in the table,…