Functions (doing a calculation) Please use speaker notes for additional information!

Functions (doing a calculation)

Please use speaker notes for additional information!

On the next two input boxes, I entered 68 and 92.

The first number is the result of adding the three inputs and dividing by 3. The second number is rounding the results of the calculation and the third number is truncating the results.

<?xml version="1.0" encoding="iso-8859-1"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><title>Function to calculate average</title><script type="text/javascript"></script></head><body><h1>Calculate Average</h1><script type="text/javascript"></script></body></html>

In this code, I am taking in three grades. The parseInt is used to convert to numeric. It is a good practice to parse for numeric. I then pas exam, proj and hmwk to the function.

The function receives the numbers and calls them exam, proj and hmwk. They are then used in the calculation to get theAvg. We then use the Math object to round (Math.round) and truncate (Math.floor). The results are shown using document.write

The average is written in the function where theAvg, theAvgRounded and theAvgFloor were declared. If I tried to write these averages outside the function, it would not work because JavaScript could not see them.

The lines giving the average were written inside the function. The last line was written in the body, outside the function.

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><title>Function to calculate average</title><script type="text/javascript"></script></head><body><h1>Calculate Average</h1><script type="text/javascript"></script></body></html>

<?xml version="1.0" encoding="iso-8859-1"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><title>Function to calculate average</title><script type="text/javascript"></script></head><body><h1>Calculate Average</h1><script type="text/javascript"></script><p>You should note that when I define theAvg using var this does not work because theAvg in the body does not see it. That is because variablesdefined within a function are local. If you define them outside the function theyare global. Omitting the word var gets around this but is not considered a great codingtechnique.</p></body></html>

<?xml version="1.0" encoding="iso-8859-1"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><title>Function to calculate average</title><script type="text/javascript"></script></head><body><h1>Calculate Average</h1><script type="text/javascript"></script><p>In this example, I used the return to return theAvg. In this case it will berecognized outside the function.</p></body></html>

<?xml version="1.0" encoding="iso-8859-1"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><title>Function to calculate average</title><script type="text/javascript"></script></head><body><h1>Calculate Average</h1><script type="text/javascript"></script><p>In this example I defined theAns outside the function which made it global. I defined theAvg inside the function and then assigned the results to theAvg as I left the function. Since it is global I can then see it.</p></body></html>

<?xml version="1.0" encoding="iso-8859-1"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><title>Function to calculate average</title><script type="text/javascript"></script></head><body><h1>Calculate Average</h1><script type="text/javascript"></script><p>In this example I defined theAns outside the function which made it global. I definedtheAvg inside the function and then assigned the results to theAns as I left the function.Since it is global I can then see it.<BR>Note that when I define the variables as I did, outside the function, I do not need topass. Preferred methodology is to pass. In fact, usually you use separate names tomaintain the integrity of the data.</p></body></html>

<?xml version="1.0" encoding="iso-8859-1"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><title>Function to calculate average</title><script type="text/javascript"></script></head>

<body><h1>Calculate Average</h1><script type="text/javascript"></script><p>In this example I defined theAns outside the function which made it global. I defined theAvg inside the function and then assigned the results to theAns as I left the function. Since it is global I can then see it.<br />Here I am using separate names for the data inside the function and outside the function to maintain the integrity of the data.</p> </body></html>

Because there is nothing after the message in the prompt to indicate the entry in the prompt box, undefined is used.

<?xml version="1.0" encoding="iso-8859-1"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><title>Function to calculate average</title><script type="text/javascript"></script></head>

<body><h1>Calculate Average</h1><script type="text/javascript"></script><p>In this example I defined theAns outside the function which made it global. I definedtheAvg inside the function and then assigned the results to theAns as I left the function.Since it is global I can then see it.<br />Here I am using separate names for the data inside the function and outside the functionto maintain the integrity of the data. I am also changing the value of the data afterit has been passed.</p></body></html>

<?xml version="1.0" encoding="iso-8859-1"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><title>Function to calculate average</title><script type="text/javascript"></script></head>

<body><h1>Calculate Average</h1><script type="text/javascript"></script><p>In this example I am calculating theAvg and then returning it using return. Note that I call the function within the write.</p></body></html>

Functions (doing a calculation) Please use speaker notes for additional information!

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