Variables are used to store values during a program’s execution. So, variables are place values in which you can leave values and recall them at will.
Declaring Variables : In most programming languages, variables must be declared in advance for the compiler.
Explicit Declarations : To declare a variable, use the Dim statement followed by the variable’s name and type as follows :
o Dim Meters as Integer
o Dim Names as String Implicit Declarations : When Visual Basic meets an undeclared variable name, it creates a new variable on the spot and uses it. The new variable’s type is variant, the generic data type that can accommodate all other data types.
The reserved word Dim is really short for dimension, which means ‘Size’. When you declare a variable, the amount of memory reserved depends on its data type. In the Dim statement [as data type] is optional. If you omit that statement the default data type is applied to the variable.
Dim var1, var2
The var1 variable is a string variable, and var2 is a numeric one.
Types of Variables
Integer data type can store any whole numbers with in the range -32,768 to 32,767.
String is also the most commonly used data type which can store Alphabetical data like letters, digits, other characters.
Variant data type is default data type which can store the any kind of data like Integer, String, Object etc.
Currency stores Decimal fractions, such as dollars and cents.
The date is also a data type which stores eight-character date.
Double-precision floating-point numbers with 14 digits of accuracy.
Larger whole number.
Object : An object variable refers to one of Visual Basic’s many objects, and you can use an object variable to access the actual object.
Variant : This is the most flexible data type because it can accommodate all other types.