Shortest way to check for null and assign another value if not

Question

I am pulling varchar values out of a DB and want to set the string I am assigning them to as    if they are null  I m currently doing it like this   if  string IsNullOrEmpty planRec approved by     true    this approved by       else   this approved by   planRec approved by toString      There seems like there should be a way to do this in a single line something like   this approved by         planRec approved by toString      However I can t find an optimal way to do this   Is there a better way or is what I have the best way to do it

User · Answer

Starting with C  8 0  you can use the     operator to replace the code of the form  if  variable is null        variable   expression      with the following code   variable     expression    More information is here

User · Answer

Use the C  coalesce operator         if Value is not null  newValue   Value else if Value is null newValue is YournullValue var newValue   Value    YourNullReplacement

User · Answer

You can also do it in your query  for instance in sql server  google ISNULL and CASE built-in functions

User · Answer

To extend  Dave s answer   if planRec approved by is already a string  this approved by   planRec approved by

User · Answer

My guess is the best you can come up with is  this approved by   IsNullOrEmpty planRec approved by    string Empty                                                         planRec approved by ToString      Of course since you re hinting at the fact that approved by is an object  which cannot equal      this would be rewritten as  this approved by    planRec approved by    string Empty  ToString

User · Answer

I use extention method SelfChk   static class MyExt     Self Check   public static void SC this string you ref string me                me   me    you            Then use like   string a   null   A  SC ref a

User · Answer

The coalesce operator      is what you want  I believe

User · Answer

You are looking for the C  coalesce operator       This operator takes a left and right argument   If the left hand side of the operator is null or a nullable with no value it will return the right argument   Otherwise it will return the left    var x   somePossiblyNullValue    valueIfNull

User · Answer

To assign a non-empty variable without repeating the actual variable name  and without assigning anything if variable is null    you can use a little helper method with a Action parameter   public static void CallIfNonEmpty string value  Action lt string gt  action        if   string IsNullOrEmpty value           action value       And then just use it   CallIfNonEmpty this approved by   s    gt  planRec approved by   s

User · Answer

Try this   this approved by   IsNullOrEmpty planRec approved by         planRec approved by toString      You can also use the null-coalescing operator as other have said - since no one has given an example that works with your code here is one   this approved by   planRec approved by    planRec approved by toString      But this example only works since a possible value for this approved by is the same as one of the potential values that you wish to set it to   For all other cases you will need to use the conditional operator as I showed in my first example

User · Answer

With C 6 there is a slightly shorter way for the case where planRec approved by is not a string   this approved by   planRec approved by  ToString

[c#] Shortest way to check for null and assign another value if not

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