Using Conditional Expressions

Using Conditional Expressions

One of the most useful tools for processing information in an event procedure is a conditional expression. A conditional expression is a part of a complete program statement that asks a True-or-False question about a property, a variable, or another piece of data in the program code. For example, the conditional expression

Price < 100

evaluates to True if the Price variable contains a value that is less than 100, and it evaluates to False if Price contains a value that is greater than or equal to 100.

You can use the following comparison operators in a conditional expression:

Comparison operator	Meaning
=	Equal to
<>	Not equal to
>	Greater than
<	Less than
>=	Greater than or equal to
<=	Less than or equal to

The following table shows some conditional expressions and their results. You'll work with conditional expressions in an exercise later in this chapter.

Conditional expression	Result
10 <> 20	True (10 is not equal to 20)
Score < 20	True if Score is less than 20; otherwise, False
Score = Label1.Text	True if the Text property of the Label1 object contains the same value as the Score variable; otherwise, False
TextBox1.Text = "Bill"	True if the word “Bill” is in the first text box; otherwise, False