Intro to Excel VBA Programming

Intro to VBA ProgrammingIvey Technology Club

Agenda Variables

Types Declaration Assignment

Functions/Subroutines Parameters Returning values

Loops While For

Intro to VBA Programming

Agenda Variables

Types Declaration Assignment

Functions/Subroutines Parameters Returning values

Loops While For

Intro to VBA Programming

You’ve seen variables before X = 5 Y = X + 3

Variables can be reused and changed X = 5 X = 2 X = X + 7

The same principles apply in programming

Variables Functions

Intro to VBA Programming

Loops

Computers are stupid Must tell them exactly what to do The more we tell them, the faster they run

Each language does this differently We will focus on VBA

Variables Functions

Intro to VBA Programming

Loops

All variables should be declared first This will prevent hard to find errors

It is not required that you do so, but HIGHLY encouraged

To force yourself, use “Option Explicit” at the beginning of VBA files

Variables Functions

Intro to VBA Programming

Loops

To declare a variable in VBA, the basic structure is:

Dim <name> as <type>

Ex. Dim X as Integer

Variables Functions

Intro to VBA Programming

Loops

Dim means “new Dimension” Fancy VBA way of saying new variable

When declaring a variable, you should know what it will be used for

Different variable types are used to store different data

Variables Functions

Intro to VBA Programming

Loops

Types include: Integer (whole numbers like 3) Float (decimal numbers like 1.25) Double (just like float, can store wider range

of values) Characters (like ‘a’) String (a number of characters in a row

such as “Ivey”)

MANY more

Variables Functions

Intro to VBA Programming

Loops

Types include: Integer (whole numbers like 3) Float (decimal numbers like 1.25) Double (just like float, can store wider range

of values) Characters (like ‘a’) String (a number of characters in a row

such as “Ivey”)

MANY more

Variables Functions

Intro to VBA Programming

Loops

To assign a value to a use the “=“ operator

Ex. Dim x As Integer (declare the

variable) x = 5

Variables Functions

Intro to VBA Programming

Loops

Agenda Variables

Types Declaration Assignment

Functions/Subroutines Parameters Returning values

Loops While For

Intro to VBA Programming

Functions Take in input, process it, and produce

output

Variables Functions

Intro to VBA Programming

Loops

Variables Functions

Intro to VBA Programming

Loops

Functions must also be declared

General format of function declaration:

Function <name>(ByVal <parameterName> As <type>) As <returnType>

Subroutines are declared the same way, but do not have a return type

Variables Functions

Intro to VBA Programming

Loops

ByVal refers to “by value” This will make a copy of the variable and its

value

ByRef could also be used This will modify the original variable

Don’t worry too much about this for now

Variables Functions

Intro to VBA Programming

Loops

To explicitly return a value from a function, assign the return value to the function name itself

Variables Functions

Intro to VBA Programming

Loops

Subroutines are the same as functions, except for 2 important differences:

1. They do not have explicit return types

2. They cannot be used directly in the spreadsheet

Agenda Variables

Types Declaration Assignment

Functions/Subroutines Parameters Returning values

Loops While For

Intro to VBA Programming

Loops Loops allow us to repeatedly perform

the same task easily

There are different kinds of loops including:

While Until For

Variables Functions

Intro to VBA Programming

Loops

Intro to VBA Programming

“While” loops while a certain condition is true

“Until” loops until a certain condition is true

“For” loops for a specified number of iterations

Variables Functions Loops

Questions, anyone ?

Intro to VBA Programming