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iOS Object-Oriented Objective-C Tying it All Together Cumulative Review

Posted by Calvin Hu
Calvin Hu
670 Points

How to find average using for in loop

Helppp, so confusing. Also what is wrong with the ; ?

variable_assignment.mm 
NSArray *temps = [NSArray arrayWithObjects:
                 [NSNumber numberWithDouble:75.5],
                 [NSNumber numberWithDouble:83.3],
                 [NSNumber numberWithDouble:96],
                 [NSNumber numberWithDouble:99.7],
                nil];

float average = nil;
float runningTotal;
for (NSArray *in temps){

};

1 Answer

landonferrier
landonferrier
25,097 Points

Calvin, here is the code that I got to pass the challenge: 

NSArray *temps = [NSArray arrayWithObjects:
                 [NSNumber numberWithDouble:75.5],
                 [NSNumber numberWithDouble:83.3],
                 [NSNumber numberWithDouble:96],
                 [NSNumber numberWithDouble:99.7],
                nil];

float average = nil;
float runningTotal;
for (NSNumber *a in temps){

    runningTotal += [a floatValue]; 
};

average = (runningTotal / temps.count);

In order to add the values to the total, we need to get them in the form of an NSNumber instead of an array, because an array is what we are looping through. Then, the average is equal to the total divided by the number of terms in the array.

If you have any questions, feel free to ask.