Vbs not equal to null

Empty strings are used quite commonly in various programming scenarios to represent a blank text field. Empty strings are initialized like this:. A null string does not refer to an instance of a System. String object and any attempt to call a method on a null string results in a NullReferenceException. In the above code we created a string Object and assigned Nothing and next we check the string is null or not. IsNullOrEmpty is a convenience method that enables you to simultaneously test whether a String is Nothing or its value is Empty.

It is equivalent to the following code:. NullReferenceException indicates that you are trying to access member fields, or function types, on an object reference that points to null. That means the reference to an Object which is not initialized. More about Home C VB. Tip The term "null" is simply a different name for "Nothing.

NET program that uses String. Null versus nothing. Nothing is not just like null in C. Instead, it has a special behavior when used with value types—it acts like the default. Note Thanks to Matthieu Penant for pointing out that Nothing has a separate meaning on value types.

Is, IsNot. References can be compared with the "Is" and "IsNot" operators. In VB. Value types cannot be equal to null. But with the Nullable structure, we can wrap an Integer and set it to null with Nothing. This can help programs be clearer. A summary. Nothing has two meanings. With references, it means a reference that points to no object.

And with values, it means the default zero-initialized value. On references, Nothing is null. It may provoke a NullReferenceException. This statement will only pass through a string that isn't empty. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. String is not null, empty, or empty string Ask Question.

Asked 7 years, 3 months ago. Active 4 years, 2 months ago. Viewed 62k times. Control Freak TruthOf42 TruthOf42 1, 3 3 gold badges 16 16 silver badges 35 35 bronze badges. Is there a String class in classic ASP? Therefore, VBScript does not have a string class like. If you need to verify your variable's type to ensure it's a string, look to the more complicated answers below. It also works for types other than string Add a comment. Active Oldest Votes. Horner Ekkehard.

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