CS 0004 –Lecture 3Jan 10, 2011
Roxana Gheorghiu
Controls (components) = building block of a GUI ◦ Labels◦ Textboxes◦ Buttons◦ Check boxes◦ Radio buttons
Variables = identifiers used in a program to hold some data
◦ Algebra: x=5; y=x*x;◦ VBA:
Dim x as Integer Dim y as Integer x =5 y =2*x
VBA Controls and Variables
Each type is design to store a particular type of data
Possible data types: Integer: -1000, 10, 0, 20000Double: -10.5, 0.0, -200.3456String : “ this is a string”, “anotherOne”Date…
2-phase process DeclarationAssignment of value (usage)
Variable Types
Create the container
DeclarationsPhase that creates a variableDim varName as Type
Dim name as String or Dim x as Integer or …Rules for variable names:
Can only use letters, numbers and underscore (_)Must start with a letter or underscoreCannot have spacesCannot use special charactersCannot be a keyword
PriceAsInteger
Fill the containerAssignment of value =gives the variable a value
By assigning a valuemyName =“Roxana”; shoesPrice =30
By assigning a value from another variablenewAddress =oldAddress
By using arithmetic operations PriceAsInteger1
00000
Fill the containerAssignment of value =gives the variable a value
By assigning a valuemyName =“Roxana”; shoesPrice =30
By assigning a value from another variablenewAddress =oldAddress
By using arithmetic operations
Addition: +◦ x = 5+5; x=y+5
Subtraction: -◦ x = 100 -2; myBudget =mySalary -2000
Division: /◦ z = X/2
Multiplication: *◦ x = 10*y◦ y = 2*5;
Exponentiation: ^◦ y = x^2◦ z = 2^3
Arithmetic operations
Incrementing Numbers
Dim x as Integer
x =x+1 OR x+ =1
Decrementing Numbers
Dim y as Integer
y=y-1 OR y-=1
Arithmetic Shorthand
RoundingMath.Round(number, precision)
Math.Round(2.182 , 1) =2.2Math.Round(2.182) =2.0
Modulo =the reminder after you divide the two numbers5 Mod 3 =221 Mod 2 =1
Square RootMath.Sqrt(9)
More Arithmetic Operations
Compute the perimeter
Write a program that :Allows a user to give two values: length and widthreads the values of length and the width computes the perimeter when Calc button is
pressed. displays this value on the screen.exits when Exit button is pressed
