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Learn basic conventions for describing functions including function signature, passing arguments, and returning values.
Basic function format
function function_name
endfunction
Accept arguments
function function_name
pass in num1, num2, num3
endfunction
Return a value
function sum_numbers
pass in num1, num2, num3
set result to num1 + num2 + num3
return result
end function
Call a function
set sum to call sum_numbers with 5, 6, 7
Example pseudocode from video
function calculate_gpa
pass in student_grades
set grade_total to 0
for each grade in student_grades
if grade is not a 1, 2, 3, or 4
print "invalid grade"
print grade
print "can't complete calculation"
exit function
else add grade to grade_total
endif
endfor
set gpa to grade_total / number of grades
return gpa
endfunction
set reggie_grades to 4, 4, 3, 4
set reggie_gpa to call calculate_gpa with reggie_grades
print reggie_gpa
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Let's change the pseudo code from the last
video to describe a reusable function
0:01
named student_grades.
0:05
In doing this, we're actually improving
our code by thinking through different
0:07
versions of our program, all without
actually having to write any code.
0:11
In other words, using pseudo code first,
as you think through and
0:14
improve the organization of
the code you're going to write.
0:18
If you'd like to follow along,
0:22
open the workspace associated with
this video in the gpa.text file.
0:24
With the function,
you want to identify the beginning and
0:28
the end of the function clearly like this.
0:32
In addition, you often pass one or
more values to a function.
0:34
Information the function can
use as part of its programming.
0:38
Here's a simple way to indicate that.
0:41
Most functions return to value.
0:43
So you'll add that usually
at the end like this.
0:44
Let's take the code from
the last video and change it.
0:47
I'll add a line to mark the beginning of
the function and the end of the function.
0:50
And then add a line indicate that you
pass in the grades for the student.
0:57
Finally, instead of printing the GPA,
we just returned it.
1:03
All of the rest of the code is the same,
it's just now wrapped into a function.
1:07
To use that function or call it,
you would do something like this.
1:12
First, create a list of grades.
1:16
Then create a new variable
named reggie_gpa that you store
1:19
the results of the running function.
1:23
You can use the word call to indicate
that you're calling the function and
1:26
use with to indicate what information
you're passing to the function.
1:29
Finally, you can do something with
that new variable like print it out.
1:33
That's most of what you need to know to
write a natural language description of
1:36
a program.
1:40
To help you start using pseudocode,
I've provided a reference sheet covering
1:41
the different pseudocode conventions
I've shown you in this workshop.
1:44
You'll see that after this video.
1:47
Have fun writing pseudocode.
1:50
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