Lesson 18 Math Functions

In Visual Basic 2015, we can write codes that can perform arithmetic operations using standard arithmetic operators. However, for more complex mathematical calculations, we need to use the built-in mathematical functions in Visual Basic 2015. There are numerous built-in mathematical functions in Visual Basic 2015. Among them are Abs, Exp, Fix, Int, Rnd, Round, sqrt and more. We shall deal with trigonometric functions and Financial Functions in coming Lessons. Most mathematical functions belong to the Math class in Visual Basic 2015. However, not all mathematical functions belong to the Math class.

18.1 The Abs function

In Visual Basic 2015, the Abs function returns the absolute value of a given number.The syntax is

`Math. Abs (Number)`

Example 18.1

In this example, we shall add a text box control for the user to input his or her number and a label control to display the absolute value of the number. We need to use the Val function to convert text to a numeric value. Rename the textbox as TxtNum and the label as LblAbs.

The Code

```Private Sub BtnComp_Click(sender As Object, e As EventArgs) Handles BtnComp.Click

LblAbs.Text = Math.Abs(Val(TxtNum.Text))

End Sub
```

18.2 The Exp function

In Visual Basic 2015, the Exp function returns the exponential value of a given number. For example, Exp(1)=e=2.71828182

The syntax is

`Math.Exp (Number)`

Example 18.2

In this example, we shall add a text box control for the user to input his or her number and a label control to display the exponential value of the number. Rename the textbox as TxtNum and the label as LblAbs.

The Code

```Private Sub BtnComp_Click(sender As Object, e As EventArgs) Handles BtnComp.Click

LblExp.Text = Math.Exp(Val(TxtNum.Text))

End Sub
```

* We use the Val function to convert a string to numeric value