How get the total sum of NSNumber's from a NSArray?

Question

I have a large NSArray containing NSNumbers like 3, 4, 20, 10, 1, 100, etc...

How do I get the total sum of all these NSNumbers (3 + 4 + 20 + 10 + 1 + 100 + etc...) as one total NSInteger?

Thank you!

score 159 · Accepted Answer · answered Jun 25 '12 at 15:46

159

You can use this:

NSArray* numbers = //array of numbers
NSNumber* sum = [numbers valueForKeyPath: @"@sum.self"];

answered Jun 25 '12 at 15:46

Paul de Lange

5

This is the most elegant solution. Docs here:http://developer.apple.com/library/ios/ipad/#documentation/cocoa/conceptual/KeyValueCoding/Articles/CollectionOperators.html – Jon Mar 18 '13 at 17:22
1

This is definitely the most elegant solution. However there's a small problem. If one of the elements in the array is NSNull, it crashes. – Sumit Nathany Feb 12 '15 at 10:35
Also it's documented to do all arithmetic with `double`s. So, five years later, with the 64-bit runtime and `NSInteger` now being the same size as a `double`, that risks loss of precision when numbers are large. – Tommy Feb 24 '17 at 14:58
1

Does anyone know how to perform those `@sum.self` in Swift? – Eddie Mar 29 '18 at 07:57
This also suffers from poor performance if the array has 1000s of numbers. Better to use fast-enumeration instead – Z S Jun 14 '21 at 18:06

Alladinian · Answer 2 · 2018-02-14T09:27:09.903

20

NSInteger sum = 0;
for (NSNumber *num in myArray) {
  sum += [num intValue];
}

edited Feb 14 '18 at 09:27

answered Jun 25 '12 at 15:41

Alladinian

score 9 · Answer 3 · edited Mar 12 '14 at 09:22

9

long long sum = ((NSNumber*)[array valueForKeyPath: @"@sum.longLongValue"]).longLongValue;

edited Mar 12 '14 at 09:22

Rahul Patel

answered Jun 25 '12 at 15:41

`valueForKeyPath:` returns an object, not an integer. – Nicolas Bachschmidt Jun 25 '12 at 15:44

score 4 · Answer 4 · answered Jun 25 '12 at 15:40

4

Iterate through the array

int count = [array count];
NSInteger sum = 0;
for (int i = 0; i < count; i++) {
    sum += [[array objectAtIndex:i] integerValue];
}

answered Jun 25 '12 at 15:40

Alexander

score 3 · Answer 5 · answered Jun 25 '12 at 16:50

3

[[numbersArray valueForKeyPath:@"@sum.self"] integerValue]

answered Jun 25 '12 at 16:50

diederikh

score 2 · Answer 6 · answered Jun 25 '12 at 15:42

2

int total = 0;
for (NSNumber *number in array)
{
  total += [number intValue];
}

may this will help you

answered Jun 25 '12 at 15:42

Abhishek

6 Answers6