Objective-C - How to get sum of Boleans? - ios

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 booleans values, in my case the result will be : 2 because we have 0+1+1
The code [Update] :
-(void)markers{
CLLocationCoordinate2D tg = CLLocationCoordinate2DMake(location.latitude, location.longitude);
GMSCoordinateBounds *test = [[GMSCoordinateBounds alloc]initWithPath:path];
BOOL test3 = [test containsCoordinate:tg];
{
if (test3 == 1)
{
marker.position = CLLocationCoordinate2DMake(location.latitude, location.longitude);
}else if (test3 == 0)
{
marker.position = CLLocationCoordinate2DMake(0, 0);
}
}
}
}

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;