# Iterating over a list in a function

#1
``````n = [3, 5, 7]

def total(numbers):
result = 0
for i in range(0, len(numbers)):
result = result + n[i]
return result

``````

the error message is total([0, 3, 6]) returned 15 instead of 9

#2

The explanation
you are NOT using the PARAMETER numbers
as a =VARIABLE= within the FUNCTION total()
but you are using an outside VARIABLE n

+++ function talk
and concentrate on

• parameter
• parameter being a =local variable= within function body
• argument
• calling a function
• usage of the return statement

### 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 )``

#3

TLDR; replace n[i] with numbers[i]

#4

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