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
thanks in advance!


#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

Please read
+++ function talk
Please read the 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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