# Total([0, 3, 6]) returned 15 instead of 9

#1

Hello,

There is a mistake in my code somewhere but I can’t find it:

'n = [3, 5, 7]

def total(numbers):
result = 0
for i in n:
result += i
return result’

The error message suggests that n[2] is being added twice, which is yielding an inaccurate result. Please explain.

I appreciate the diligent work you do to help anyone learning programming. The world needs more resources like codecademy

#2
``````n = [3, 5, 7]

def total(numbers):
#4 space indent
#the numbers PARAMETER is used as a VARIABLE
#numbers will get the VALUE of the ARGUMENT given
print "== init ========================="
print "{0} {1}".format("The VALUE of =numbers= ",numbers)
result = 0
print "{0} {1}".format("init Value of =result= ",result)
for i in numbers:
#4 space indent
#FOR-loop code-block
print "== FOR loop iteration ==========="
print "{0} {1}".format("result before: ",result)
result += i
print "{0} {1}".format("result after: ",result)
#End of FOR-loop code-block
#and END-of-FUNCTION
print "== FOR loop ended ============="
print "{0} {1}".format("result VALUE to be returned",result)
return result

print total(n)
``````

##===================================================

== init =========================
The VALUE of =numbers= [3, 5, 7]
init Value of =result= 0
== FOR loop iteration ===========
result before: 0
result after: 3
== FOR loop iteration ===========
result before: 3
result after: 8
== FOR loop iteration ===========
result before: 8
result after: 15
== FOR loop ended =============
result VALUE to be returned 15
15

#3

### the FUNCTION talk

``````def myFunc( param1, param2):
# Begin of =myFunc= FUNCTION-BODY
# this =myFunc= function- has 2 PARAMETERS param1 and param2
# param1 and param2 PARAMETERS are used
# as -local- VARIABLES throughout the =myFunc= FUNCTION-BODY
print( param1 + " and " + param2 )
#End of =myFunc= FUNCTION-BODY
``````

If you want to call/execute the myFunc function
you will have to add a pair of parentheses to myFunc
like
myFunc()
As the myFunc function was defined
as having 2 parameters
you have to provide 2 arguments
in our case 2 string VALUES “Alena” and “Lauren”
like
myFunc(“Alena”,“Lauren”)

some quotes from the outer-world:

argument is the value/variable/reference being passed in,
parameter is the receiving variable used within the function/block

OR

"parameters" are called “formal parameters”,
while “arguments” are called “actual parameters”.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++++ function with 1 parameter using return-statement

``````def myFunction( param1 ):
# //Begin of =myFunction= FUNCTION-BODY
# //=myFunction= function has 1 PARAMETER param1
# //this param1 PARAMETER is used as a -local- VARIABLE
# //throughout the =myFunction= FUNCTION-BODY
return param1;
# //End of FUNCTION-BODY
``````

You have defined a myFunction function
which takes 1 parameter param1
this param1 parameter is used
as a variable throughout the =myFunction= FUNCTION-BODY.

If you want to call/execute this myFunction function
and this myFunction function was defined
as having 1 parameter param1
you will have to provide 1 argument
in our case a “number VALUE” 4
myFunction( 4 )

some quotes from the outer-world:

argument is the value/variable/reference being passed in,
parameter is the receiving variable used within the function/block

OR

"parameters" are called “formal parameters”,
while “arguments” are called “actual parameters”.

#### ============================================

As you are using the return-statement in your myFunction function
you will only get a return-value no-display.
You can however capture this return-value in a variable
and then use the print-method to do a display.

``````theResult = myFunction( 4 )
print theResult
``````

OR directly

``print myFunction( 4 )``

#4