Example. This example shows some Mod expressions with constant Integers. When the value 90 goes into 1000 11 times, but leaves a remainder of 10. This is the result of 1000 Mod 90.
And The next Mod expressions show the same principle in action. The Console output is shown.
Module Module1
Sub Main()
' Compute some modulo expressions with Mod.
Console.WriteLine(5 Mod 3)
Console.WriteLine(1000 Mod 90)
Console.WriteLine(100 Mod 90)
Console.WriteLine(81 Mod 80)
Console.WriteLine(1 Mod 1)
End Sub
End Module2
10
10
1
0
Loop example. Using a Mod expression is appropriate in a For-loop. You can apply Mod to the variable "i". In this program, we display "i" whenever it is divisible by 10.
Detail This style of code is useful in real programs. We can "throttle" an action to occur only occasionally this way.
Module Module1
Sub Main()
' Loop through integers.
For i As Integer = 0 To 200 - 1
' Test i with Mod 10.
If i Mod 10 = 0 Then
Console.WriteLine(i)
End If
Next
End Sub
End Module0
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Odd, even numbers. The parity of a number is whether it is odd or even. We can test parity by creating 2 functions in VB.NET that return true or false.
Note IsOdd returns the opposite of IsEven. It correctly handles negative and positive numbers.
Note 2 IsEven uses modulo division (with Mod) to see if the number is evenly divisible by 2 (and thus even).
Info Both methods return a Boolean (true or false). We test these methods with a simple For-loop.
Module Module1
Function IsOdd(ByVal number As Integer) As Boolean
' Handle negative numbers by returning the opposite of IsEven.
Return IsEven(number) = False
End Function
Function IsEven(ByVal number As Integer) As Boolean
' Handles all numbers because it tests for 0 remainder.' ... This works for negative and positive numbers.
Return number Mod 2 = 0
End Function
Sub Main()
For i = -10 To 10
Console.WriteLine(i.ToString() + " EVEN = " + IsEven(i).ToString())
Console.WriteLine(i.ToString() + " ODD = " + IsOdd(i).ToString())
Next
End Sub
End Module-10 EVEN = True
-10 ODD = False
-9 EVEN = False
-9 ODD = True
-8 EVEN = True
-8 ODD = False
-7 EVEN = False
-7 ODD = True
-6 EVEN = True
-6 ODD = False
-5 EVEN = False
-5 ODD = True
-4 EVEN = True
-4 ODD = False
-3 EVEN = False
-3 ODD = True
-2 EVEN = True
-2 ODD = False
-1 EVEN = False
-1 ODD = True
0 EVEN = True
0 ODD = False
1 EVEN = False
1 ODD = True
2 EVEN = True
2 ODD = False
3 EVEN = False
3 ODD = True
4 EVEN = True
4 ODD = False
5 EVEN = False
5 ODD = True
6 EVEN = True
6 ODD = False
7 EVEN = False
7 ODD = True
8 EVEN = True
8 ODD = False
9 EVEN = False
9 ODD = True
10 EVEN = True
10 ODD = False
Syntax note. In C-like languages, the "%" character expresses a modulo division. We cannot use this character in VB.NET. Instead the Mod operator is used.
A summary. Modulo division is an important concept to understand in computer programming. In .NET, modulo division is used to implement collections such as Dictionary.
The Mod operator often comes in handy whenever a mathematical procedure is needed. We can use modulo for determining parity (odd or even).
Dot Net Perls is a collection of tested code examples. Pages are continually updated to stay current, with code correctness a top priority.
Sam Allen is passionate about computer languages. In the past, his work has been recommended by Apple and Microsoft and he has studied computers at a selective university in the United States.
This page was last updated on Aug 8, 2023 (edit link).
