The variant data type is vbas default, so the following code interprets varvalue as a variant. If you omit the data type, vba applies the variant data type to your variableits the most flexible and vba wont guess at what the data type should be. When a variable is declared, a data type is supplied for it that determines the kind of data they can store. Paul lomaxs explanation of the language comes in two main parts. Vba how to declare an array with elements with different. Here are a few notes to keep in mind when using data types. If you are using excel vba, remember that vba is essentially vb6, and hence those rules apply.
If you omit the data type, vba applies the variant data type to your variableits the most flexible and vba wont. Apr 16, 2018 a variant is a data type for variables. Although vba can handle your data automatically without worrying about the data types, the resulting program executes very slowly and uses memory inefficiently. String, boolean, integer and double are 4 of the most common vba data types. It is always added to some other value to indicate an array of a particular type. The vba language offers a full set of the usual data types, plus a smart data type called a variant, which is the chameleon of the programming world, adapting itself seamlessly to hold any type of data. One example might be a simple data entry system to track your personal finances. Variant is used when youre not sure what value will be returned.
The data type of a variable determines the kind of data the variable can hold. Dim myvar1 as integer, myvar2 as string, somedate as date. In general, you can document your code using the data type conversion functions to show that the result of some operation should be expressed as a particular data type rather than the default data type. A variant containing an array requires 12 bytes more. This enables you to store any kind of data in the variable. A public fixedlength string cant be used in a class module. Data types in visual basic can be divided into three groups. This is because, as explained by richard mansfield in mastering vba for microsoft office 2016. For example, use ccur to force currency arithmetic in cases where singleprecision, doubleprecision, or integer arithmetic normally would occur. Dim varvalue although the variant data type is flexible, vba processes these data types a little slower because it must determine the most accurate data type for the assigned value. Variables and data types in excel vba example programs.
A new data type can be defined using the type statement. Examples of data types are integers, floating point numbers, and strings. This chapter lists the data types available in vba and discusses a complete range of issues related to data types, including variable scope. As a general rule you should use variant for data where you wont know what type of input will be used. Return value an integer representing the data type of varname.
Each data type has limits to the kind of information and the minimum and maximum values it can hold. By default visual basic variables are of variant data types. You specify a data type by including the as keyword in a dim statement. To confirm this, you can step into the code and check the types in the locals window. A variable that holds integers whole numbers has the data type integer and is called an integer variable. Feb 05, 2015 in vba, that declares dproduct and dquantity as variant types, not double types.
Visual basicdata types wikibooks, open books for an open world. Use long if you have larger numbers up to 2,147,483,647. Variables and data types writing word macros, second. Default type if the variable is not declared with any data type. Suffice it to say, vba offers over a dozen data types to store numbers, text and objects.
The data coming in from excel is mixed, of course, so a value column that accepts whatever data it is given would be groovy. The vba vartype function returns information on the vba data type of a given variable. In excel vba programming for dummies, john walkenbach likens the. Therefore, vba is able to handle the details related to data types automatically. Be sure to set a reference to visual basic for applications extensibility 5. Option explicit option base 1 sub testvars be sure to set a reference to visual basic for applications extensibility 5. Visual basic 6 vb6 data types, modules and operators. A variant can contain a value of any of the types listed in table 4. Vba is the programming language we use to create macros.
Nov 19, 2018 a fixedlength string can contain 1 to approximately 64 k 216 characters. However, most likely, youll never notice the performance hit. Visual basicdata types wikibooks, open books for an. A variant allows vba to make its own decision as to what type of data it is holding. Vba vartype function check the data type of a excel vba.
First, lomax explains the structure and syntax of visual basic vb and visual basic for applications vba programs. The variant data type is capable of holding any type of data except fixedlength strings and user defined types. Have questions or feedback about office vba or this documentation. The topics range from networking to artificial intelligence and from database. As you may have noticed, vb supports several data types. Refer the below table for return value for all the data types. A tag is stored with the variant data to identify the type of data that it currently contains. An array of type variant can store any data type in any of its elements.
The graphic below describes these most common vba data types. Vba data types using variables, constants, and data types in. Any ideas, i thought there would be something along the lines of. However, using it too much can slow down your programmes, as it uses 16 bytes of data for numbers and 22 bytes for text. A variant is a com data type that is used for storing and exchanging values of arbitrary types, and any other. It returns a number corresponding to one of the values of the vbvartype vba enum object the excel vba vartype function comes useful in a variety of scenarios especially when we are passing variant objects into a vba sub or function as a parameter. For reference, table 51 shows the complete set of vba data types, along with the amount of memory that they consume and their range of values. These are what the main types that you can declare your variables as. It will then examine the ways in which variables are declared in visual basic and discuss variable scope, visibility, and lifetime. Variable data types understanding program variables in vba. Specifying a data type wont keep you from entering an invalid value, but it will keep you from entering an invalid type. Vba works with a variety of data types to help you make adjustments to windows programs. A variant variable can freely change its type at runtime, whereas one that has been specified as, for example, a string cannot.
An array with the variant data type can store multiple subtypes of data. Variable data types understanding program variables in. Vba has builtin such as boolean and application specific data types such as range in excel. The first 128 characters 0127 of the character set correspond to the letters and symbols on a standard u. The design allows for code to be tighter and leaner. Once created, we can manipulate these userdefined types directly by creating variables,or constants,of that data type throughout the program for which it is defined. The variant data type is vba s default, so the following code interprets varvalue as a variant. The default vba data type is called variant, and i explain it below. Variant is a data type in certain programming languages, particularly visual basic, ocaml. The variant data type excel vba programming the complete. Variant type take more space in memory than any other variable here youll find the code for the macro, to test, i just added the routine for variant there are some other factors that may be in play for this, its a very subjective topic as such this is my personal experience.
Vba variables declaring using vba dim and vba data types. The variant data type can store numeric, datetime or string data. One of the few instances in which you have no choice for using a variant. I have a list which is populated with fields from a table, i want to be able to determine if the data type of the value selected in the list is number.
Vba data types automating microsoft access with vba. Let see an example, on how to declare variables in vba. Jul 14, 2001 as you may have noticed, vb supports several data types. In this example, we will declare three types of variables string, joining date and currency. You always should tell visual basic what sort of data the variable will hold. Visual basic for applications isnt one of these languages. Integer can store positive and negative numbers between 32,768 and 32,767.
The vartype function never returns the value for vbarray by itself. The variant data type can be used to define variables that contain any type of data. The following table shows the standard vba data types, how big they are and describes their functions. A fixedlength string can contain 1 to approximately 64 k 216 characters. Dim astritems0 to 9 as string dim varitems as variant varitems astritems. He has writing in his blood, having produced 71 books and over 300 articles to date. A data type is the characteristic of a variable that determines what kind of data it can hold. A variable supports more than just primitive data types like numbers and strings. More precisely, if you dont declare the vba data type for a particular variable, visual basic for applications uses the default type. The fundamental data types in visual basic including variant are integer, long, single, double, string. You can use the function vartype to find out the type of data held by a.
It is most useful when you may get, as the name implies, a variety of data. The excel vba vartype function comes useful in a variety of scenarios especially when we are passing variant objects into a vba sub or function as a parameter. Data types and variables t his chapter will begin by examining the intrinsic data types supported by visual basic and relating them to their corresponding types available in the. It can also be assigned to any object in the excel object model a worksheet, a workbook, etc. In such a case, the array data type must be variant. Step 1 like, in the previous tutorial, we will insert the commandbutton1 in our excel sheet. Vba notes for professionals free programming books. About the book author john mueller is a freelance author and technical editor. Userdefined data types in vba for excel tutorial 11 may. Does anyone have or know where i can locate the list of vba data types and. The constant vbvariant is only returned in conjunction with vbarray to indicate that the argument to the vartype function is an array of type variant.
In addition, some types can interchange with some other types. I suspect these 4 data types will be all you need for well over 90% of your vba macros. Variant type news newspapers books scholar jstor may 2019 learn how and when to remove this template message. In this lesson, we use the typename method from the vba object to track the data type of a variant variable as we assign different values to it. Vba data types using variables, constants, and data. The languages documents the latest version of the worlds bestselling rapid application development environment. It returns a number corresponding to one of the values of the vbvartype vba enum object.
One final variable type that can come in handy is variant. I will discuss a few of the more commonly used data types in a moment. Visual basic for applicationsredundant variables list. The manner in which a program stores data in memory is referred to as the data type. The reason i wish to do this is, because i am creating a query in vba and in the where clause i use in, and it is giving me a datatype mismatch whenever it is sent a number data type. The variant data type is the data type for all variables that are not explicitly declared as some other type using statements such as dim, private, public, or static the variant data type has no type declaration character a variant is a special data type that can contain any kind of data except fixedlength string data. An exception to this rule is if you want the array to hold different data types. Returns the data type of the variable or type of the data stored in this variable. However, this isnt a good idea because variant variables use more memory and are much slower than the other data types. If you dont include a data type when declaring a variable, vba assigns the variant data type. This chapter lists the data types available in vba and discusses a complete range of issues related to data types, including variable scope and. Although the variant data type is flexible, vba processes these data types a little slower because it must determine the most accurate data type for the assigned value. A variant can store all kinds of data, whether it is text, numbers, dates, or other information.
The variant data type is the data type for all variables that are not. The variant data type can be used for all data types. Variant data type field in access 2003 solutions experts. In vba, if the data type is not specified, it will automatically declare the variable as a variant. Vba vba notes for professionals notes for professionals free programming books disclaimer this is an uno cial free book created for educational purposes and is not a liated with o cial vba groups or companys.
Well user input can always be put in a string variable, but the main thing i want to say is that i would turn the first sentence around and say never use a variant unless you absolutely have to. Classes include forms, addins, and database designers. The fundamental data types in visual basic including variant are integer, long, single, double, string, currency, byte and boolean. The dproduct and dquantity variables have been prefixed with d, which implies they are doubles when they arent. In other words, this is the data type that visual basic for applications uses when you dont determine the type yourself at the moment of declaring a variable. First it helps to have a real project, not a made up fake project you dont care about. You can examine the tag by using the vartype function. The following table shows the supported data types, including storage sizes and ranges. You can also use the dim statement to declare multiple variables in one line using the vba dim statement. Data types include those in the following table as well as userdefined types and specific types of objects. You can, however, also declare a variant variable explicitly. When we run the sub, vba goes through all the lines of code and carries out the appropriate actions. The sql statement created produces something along the lines of. Vba data types using variables, constants, and data types.
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