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Start your free trialLuis Paulino
Courses Plus Student 1,779 PointsI know my problem is inside the for in loop, what can I do to improve the code?
I f*ck up with running the average, x float value, through runningTotal. It's does miner errors that trip me up, but this is just my second attempt so it's not too bad.
NSArray *temps= @[@75.5, @83.3, @96, @99.7];
float average;
float runningTotal;
for(NSNumber *temps in tempsArray ){
float runningTotal( xfloatValue && flat avarage);
}
1 Answer
Steve Hunter
57,712 PointsHi Luis,
You've nearly done that - very close!
A few points to make. Here:
for(NSNumber *temps in tempsArray)
The loop will iterate over an array holding each value in the array, in turn, within the local variable declared there. Your array is called temps
so you'll need to call your local variable something different. Just use x
; it's easy! And tempsArray
doesn't exist; change that to temps
. That gives us:
for(NSNumber *x in temps){
// add up all the x's
}
We want to add the value held by x
into runningTotal
at each iteration. You've got:
float runningTotal( xfloatValue && flat avarage);
First, don't redeclare runningTotal
as a float
; omit the float
word as the compiler knows runningTotal
is a float
already. Next, ignore average
for now - we come to that later. You can't create the average inside the loop. What we're doing is adding up all the elements of temps
with the loop, we'll then divide by the length of temps
after the loop and store the result of that in average
.
Inside the loop, you want to add to runningTotal
with +=
just like you have done. But we need to convert the NSNumber
into float
. Use square brackets and floatValue
for that:
runningTotal += [x floatValue];
That completes the loop. It looks like:
for(NSNumber *x in temps){
runningTotal += [x floatValue];
}
Now, find the number of elements in the temps
array. Use the count
property and square brackets again [temps count]
, and divide runningTotal
by that. Store the result in average
.
Let me know how you get on.
Steve.