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New page: Two areas where computer systems excel are arithmetic and logic. Given this fact, it should come as no surprise that a lot of programming tasks also involve arithmetic and logic. The purpo...
Two areas where computer systems excel are arithmetic and logic. Given this fact, it should come as no surprise that a lot of programming tasks also involve arithmetic and logic. The purpose of this chapter is to cover both these topic areas in the context of Visual Basic programming.
== Understanding Expressions ==
Arithmetic calculations and logical evaluations are defined in Visual Basic using ''expressions''. The calculation 1 + 1 is, for example, an expression.
Expressions consist of two key components called ''operators'' and ''operands''. The ''operands'' define the values or variable on which the arithmetic or logical evaluation are to be made. The ''operator'' defines what action is to be performed on the operands. Often, an ''assignment'' operator is also used to define what should happen to the result of the expression. This is, perhaps, best explained using an example:
<pre>
Dim intResult As Integer
intResult = 4 + 5
</pre>
In the above example, the numbers '4' and '5' are both ''operands''. The '+' is an ''operator'' which adds together the two ''operands''. Similarly, the '=' is an ''operator'' which assigns the result of the addition to the ''intResult'' variable which is an operand.
A logical expression uses operators and operands to make a decision of some sort. For example:
<pre>
Dim intResult As Integer = 10
If intResult < 20 Then
MessageBox.Show("Result is less than 10")
</pre>
== Understanding Expressions ==
Arithmetic calculations and logical evaluations are defined in Visual Basic using ''expressions''. The calculation 1 + 1 is, for example, an expression.
Expressions consist of two key components called ''operators'' and ''operands''. The ''operands'' define the values or variable on which the arithmetic or logical evaluation are to be made. The ''operator'' defines what action is to be performed on the operands. Often, an ''assignment'' operator is also used to define what should happen to the result of the expression. This is, perhaps, best explained using an example:
<pre>
Dim intResult As Integer
intResult = 4 + 5
</pre>
In the above example, the numbers '4' and '5' are both ''operands''. The '+' is an ''operator'' which adds together the two ''operands''. Similarly, the '=' is an ''operator'' which assigns the result of the addition to the ''intResult'' variable which is an operand.
A logical expression uses operators and operands to make a decision of some sort. For example:
<pre>
Dim intResult As Integer = 10
If intResult < 20 Then
MessageBox.Show("Result is less than 10")
</pre>