Objective-C - How to get sum of Boleans?

Question

Through the code below, I can get an output such as :
0
1
1

What I want is to output the sum of these boolea

Answer 1

Rather than sum BOOLs, which is counterintuitive, loop over whatever you are using to get the BOOL values, and if you get YES, increment a counter. This will be the number of YESs that you have.

If you have an array of BOOLs, you could just filter the array with a predicate to get the YES values and the length of the resulting array is the number of YESs that you have.

Edited to add code samples following OP comments

Incrementing a counter

NSUInteger numberOfBools = 0;
CLLocationCoordinate2D tg = CLLocationCoordinate2DMake(location.latitude, location.longitude);
GMSCoordinateBounds *test = [[GMSCoordinateBounds alloc]initWithPath:path];
if ([test containsCoordinate:tg1]) { ++numberOfBools; }
if ([test containsCoordinate:tg2]) { ++numberOfBools: }
... // other tests here;

// numberOfBools now contains the number of passing tests.

Edited Again, after the full code was added

// snipped code above here
// This is where you add the counter and initialise it to 0
NSUInteger numberOfBools = 0;
for (NSDictionary *dictionary in array)
{            
    // Snip more code to this point
    BOOL test3 = [test containsCoordinate:tg];
    {
        if (test3)
        {
        // This is where you increment the counter
        ++numberOfBools;

// Snip more code to the end of the for block
}

// Now numberOfBools shows how many things passed test3

Answer 2

int sum = (test3 ? 1 : 0) + (testX ? 1 : 0) + (testY ? 1 : 0);

And not so weird variant:

#define BOOL_TO_INT(val) ((val) ? 1 : 0)

int sum = BOOL_TO_INT(test3) + BOOL_TO_INT(testX) + BOOL_TO_INT(testY);

Answer 3

You can just add BOOLs since bools are just integers. e.g. :

int sum = 0;

CLLocationCoordinate2D tg = CLLocationCoordinate2DMake(location.latitude, location.longitude);
GMSCoordinateBounds *test = [[GMSCoordinateBounds alloc]initWithPath:path];
BOOL test3 = [test containsCoordinate:tg];
//Obtain bolean values :

BOOL testX = /* other test */;
BOOL testY = /* other test */;

sum = test3 + testX + testY

This is a bad idea however, as BOOLs aren't necessarily 1 or 0. They are 0 and not 0

BOOL is just a typedef-ed char: typedef signed char BOOL; YES and NO are 1 and 0, but BOOL variable = 2 is perfectly valid

For example:

- (int) testX
{
    if(inState1) return 1;
    if(inState2) return 2;

    else return 0;
}

BOOL textXResult = [self testX]; //Might return 2, this is still equivalent to YES.

The best solution is to iterate your BOOLs and instead count the number of YESes.

Answer 4

Another way to do this is to assume that if any one value is false, then the entire array is false, so, loop over the array until a false value is found, then break:

BOOL retval = true;  //return holder variable

/*'boolsNumArray' is an NSArray of NSNumber instances, converted from BOOLs:

    //BOOL-to-NSNumber conversion (makes 'boolsNumArray' NSArray, below)!
    '[myNSArray addObject:[NSNumber numberWithBool:yourNextBOOL]]' 

*/
for(NSNumber* nextNum in boolsNumArray) {
    if([nextNum boolValue] == false) {
        retval = false;
        break;
    }
}

return retval;