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This lesson is called songwriting with parameters.

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We're going to be writing some songs here.

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Sometimes the chorus is just a little bit[br]different each time you sing it.

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Do you remember Old Macdonald Had a Farm?

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The chorus is slightly different for each[br]animal.

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And on that farm, he had a cow, e-i-e-i-o.

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The small change in each chorus can be shown[br]using something we call parameters.

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Sometimes a function needs a parameter.

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A parameter is an extra piece of information[br]you can pass to a function to customize it

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for a special need.

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When you make ice cream sundaes with your[br]friends, you are using a process similar to

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parameters in a computer program.

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The disk of vanilla ice cream might be the[br]same for every sundae but when you ask your

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friends which two toppings they'd like, you[br]could get lots of different combinations.

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Topping is the function name but each type[br]of topping is a parameter.

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Functions and parameters work together to[br]make great computer programs and great sundaes

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too.