4-2: Boolean Expressions

The code for the complete program is shown here:

Private Sub btnCheck_Click( ... ) ...
'
' Experiment by changing the data types of variables valueOne
' and(valueTwo)
'
Dim valueOne, valueTwo As Double
Dim compare As Boolean
'
' Assign values from the textboxes (converted appropriately)
' to the two variables.
'
valueOne = Convert.ToDouble(txtValue1.Text)
valueTwo = Convert.ToDouble(txtValue2.Text)
'
' Compare valueOne and valueTwo and assign result to variable
' compare.
' Experiment by changing the comparison operator
'
compare = (valueOne = valueTwo)
'
' Display the result of the comparison (i.e. the value of
' variable compare) in the text of the label object.
'
lblAnswer.Text = compare
End Sub

The code shows variables valueOne and valueTwo declared as Double and the comparison operator as =, but we should change these as we explore the comparison of values. Table 4-2 suggests a set of experiments you should perform. Predict the "answer" before running the program!

Table 4-2: Experimenting with Comparison Operators.

varOne data type	value1	varTwo data type	value2	Comparison Operator	Result
Double	3.2	Double	3.3	=	?
Double	3.2	Double	3.2	=	?
Double	3.2	Double	0.32e1	=	?
Double	3.2	Double	3.3	<	?
Double	3.2	Double	3.2	<	?
Double	3.2	Double	0.32e1	<	?
Double	3.2	Integer	3	=	?
Double	3.2	Integer	3	<	?
Double	1.25634735	Single	1.2563473	=	?
String	3.2	Integer	3	=	?
String	3.2	Double	3.2	=	?
String	0.32e1	Double	3.2	=	?
String	0.32e1	String	3.2	=	?
String	John	String	john	=	?