Microsoft Access New and Updated KB Posts

Arrays in Access VBA use a 0-based indice. UBound returns -1 if the array has no elements, 0 if it has 1, 1 if it has 2, etc.

In Access VBA, you have to add an empty string to the value being compared in order to get consistent results. For example, add &"" to your string varilable or it's code equivalent &vbNullString. Then compare to an empty string or verify it's length to 0 with Len.

Same as VB. The Me keyword is a built-in variable that refers to the class where the code is executing. For example, you can pass Me from one module to another.

You can deploy your Microsoft Access application either with the full version of Access or with the Access Runtime (see Deploying Applications Using the Access Runtime).

Same as VB. Access VBA logical operators:

Same as in VB6. Access VBA has limited support for interfaces. You can create an interface of abstract methods and properties and then implement them in one or more descendant classes. It's a single level implementation though (you cannot inherit beyond that). The parent interface class is a pure abstract class (all methods and properites are abstract, you cannot implement any of them in the parent class).

In the single level descendant class, you have to implement all methods and properties and you cannot add any. Your first line of code is Implements InterfaceName.

When an object instance is destroyed, Access VBA calls a special parameter-less sub named Class_Terminate. For example, when the variable falls out of scope. Since you cannot specify parameters for this sub, you also cannot overload it.

When an object instance is created from a class, Access VBA calls a special sub called Class_Initialize.

When an object instance is created from a class, Access VBA calls a special parameter-less sub named Class_Initialize. Since you cannot specify parameters for this sub, you also cannot overload it.

When a class is destroyed, Access VBA calls a special sub called Class_Terminate.

Execute more common evaluations first! Short-circuit evaluation is a feature of most languages where once an evaluation evaluates to False, the compiler evaluates the whole expression to False, exits and moves on to the next code execution line. In Access VBA, the if statement does not support short-circuit evaluation but you can mimic it. Use either an if..else if..else if statement or nested if statements. You will find that your code that makes use of this technique will be clearer and easier to maintain than the short-circuit equivalent and will execute faster than ignoring this issue.

Access VBA uses the keywords sub and function. A sub does not return a value and a function does. Many programmers like to use the optional call keyword when calling a sub to indicate the call is to a procedure.

Arrays in Access VBA use a 0-based indice. UBound returns -1 if the array has no elements, 0 if it has 1, 1 if it has 2, etc.

In Access VBA, you have to add an empty string to the value being compared in order to get consistent results. For example, add &"" to your string varilable or it's code equivalent &vbNullString. Then compare to an empty string or verify it's length to 0 with Len.

Same as VB. Access VBA logical operators:

Same as VB. The Me keyword is a built-in variable that refers to the class where the code is executing. For example, you can pass Me from one module to another.

You can deploy your Microsoft Access application either with the full version of Access or with the Access Runtime (see Deploying Applications Using the Access Runtime).

An operation with only one operand (a single input) such as + and -.

Access VBA is a loosely typed language. Declaring variables is optional unless you use the Option Explicit statement to force explicit declaration of all variables with Dim, Private, Public, or ReDim. Using Option Explicit is strongly recommended to avoid incorrectly typing an existing variable and to avoid any confusion about variable scope. Variables declared with Dim at the module level are available to all procedures within the module. At the procedure level, variables are available only within the procedure.

Scope can be Public, Global, or Private. The use of the newer Public keyword is preferred to the older Global. Private Const is the same as just specifying Const.

Access VBA, like all the VB-based languages, uses a single quote (') or the original class-style basic "REM" (most developers just use a quote). Access VBA does NOT have a multiple line comment. Directives are sometimes called compiler or preprocessor directives. A # is used for directives within Access VBA code. Access VBA offers only an #If..then/#ElseIf/#Else directive.

Access VBA is a non-OOP language with some OOP features. It offers both Subs and Functions. A Sub does not return a value while a Function does. When Subs and Functions are used in a class module, they become the methods of the class.