COMPUTER PROGRAMMING I

Objective 7.03 Apply Built-in Math Class

Functions

Objective/Essential Standard

Essential Standard7.00 Apply Advanced Logic

Indicator7.03 Apply Built-in Math Class Functions (3%)

Math Class Functions

Math Class Functions

The Math class provides programmers with numerous functions.

We will only look at a few of these functions.Abs(num)

Returns the absolute value of a positive or negative number

Sqrt(num) Returns the square root of a number

Sign(num) Returns the sign of a number

Round (num, places) Returns number nearest to the specified value.

Using Abs(num)

The Abs() function works with the following data types: Decimal, Double, Int16, Int32, Int64, SByte, Single

Abs() Function intNum Value after execution

intNum = Math.Abs(4) 4

sngNum = Math.Abs(-4.123)

4.123

intNum = Math.Abs(0) 0

Using Sqrt(num)

Returns the square root of a number as a double

Sqrt() Function dblNum Value after execution

dblNum = Math.Sqrt(4)

2.0

dblNum = Math.Sqrt(0)

0.0

dblNum = Math.Sqrt(-4)

NaN(NaN represents a value that is not a number)

Using Sign(num)

The Sign() function works with the following data types: Decimal, Double, Int16, Int32, Int64, SByte, Single

Sign() Function intNum Value after execution

intNum = Math.Sign(4)

1

intNum = Math.Sign(-4)

-1

intNum = Math.Sign(0)

0

Round Function

The Round() function works with either a decimal or a double. The variable/value that represents the number of places should be an Integer.

Round() Function dblNum Value after execution

dblNum = Math.Round(5.23651, 2)

5.24

decNum = Math.Round(5.23651)

5.0

dblNum = Math.Round(5.5) 6.0

decNum = Math.Round(5.225, 2)

5.23

Note that .5 does round up here.

Try It!

Create a new application called mathExample Save it into the location as instructed by your teacher.

Add the following controls.When the button is clicked, the appropriate answer

should be displayed in the lblAnswer label. When the btnRound is clicked, it should display an input box

to ask for the number of decimal places.

Control Name Text/Items

Label lblPrompt Enter a Number:

Label lblAnswer

Button btnAbs Absolute Value

Button btnSqrt Square Root

Button btnSign Sign

Button btnRound Round It