IsNullOrEmpty with Object

Question

IsNullOrEmpty is used with strings to check if a string is null or empty  Is there an equivalent with an object to see if any object is null or not  I assume we can do       obj1    null    but not sure if there is any other way

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You can simply compare it with System DBNull Value

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IsNullOrEmpty is essentially shorthand for the following   return str    null    str    String Empty    So  no there is no function that just checks for nulls because it would be too simple  obj    null is the correct way  But you can create such a  superfluous  function yourself using the following extension   public bool IsNull this object obj        return obj    null      Then you are able to run anyObject IsNull

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Why would you need any other way  Comparing an Object reference with null is the least-verbose way to check if it s null

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The following code is perfectly fine and the right way  most exact  concise  and clear  to check if an object is null   object obj   null          if  obj    null           Do something     String IsNullOrEmpty is a method existing for convenience so that you don t have to write the comparison code yourself   private bool IsNullOrEmpty string input        return input    null    input    string Empty      Additionally  there is a String IsNullOrWhiteSpace method checking for null and whitespace characters  such as spaces  tabs etc

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I found that DataGridViewTextBox values and some JSON objects don t equal Null but instead are       values  Comparing them to Null doesn t work but using these do the trick   if  cell Value is System DBNull   if  cell Value    System DBNull Value    A good excerpt I found concerning the difference between Null and DBNull      Do not confuse the notion of null in an object-oriented programming language with a DBNull object  In an object-oriented programming language  null means the absence of a reference to an object  DBNull represents an uninitialized variant or nonexistent database column    You can learn more about the DBNull class here

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You may be checking an object null by comparing it with a null value but when you try to check an empty object then you need to string typecast  Below the code  you get the idea  if obj    null     string  obj    string Empty         Obj is null or empty

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a null string is null  an empty string is     isNullOrEmpty requires an intimate understanding about the implementation of a string   If you want one  you can write one yourself for your object  but you have to make your own definition for whether your object is  empty  or not   ask yourself   What does it mean for an object to be empty

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obj1    null     is the right way   String defines IsNullOrEmpty as a nicer way to say  obj1    null    obj    String Empty   so it does more than just check for nullity   There may be other classes that define a method to check for a sematically  blank or null  object  but that would depend on the semantics of the class  and is by no means universal   It s also possible to create extension method to do this kind of thing if it helps the readability of your code   For example  a similar approach to collections   public static bool IsNullOrEmpty  this ICollection collection        return collection    null    collection Count    0

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object MyObject   null   if  MyObject    null  amp  amp   string IsNullOrEmpty MyObject ToString

[c#] IsNullOrEmpty with Object

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