How to calculate number of digits after floating point in iOS?

Question

How can I calculate the number of digits after the floating point in iOS?

For example:

• 3.105 should return 3
• 3.0 should return 0
• 2.2 shou

Answer 1

Maybe there is a more elegant way to do this, but when converting from a 32 bit architecture app to a 64 bit architecture, many of the other ways I found lost precision and messed things up. So here's how I do it:

bool didHitDot = false;    
int numDecimals = 0;
NSString *doubleAsString = [doubleNumber stringValue];

for (NSInteger charIdx=0; charIdx < doubleAsString.length; charIdx++){

    if ([doubleAsString characterAtIndex:charIdx] == '.'){
        didHitDot = true;
    }

    if (didHitDot){
        numDecimals++;
    }
}

//numDecimals now has the right value

Answer 2

What I used is the following:

NSString *priorityString = [[NSNumber numberWithFloat:self.priority] stringValue];
    NSRange range = [priorityString rangeOfString:@"."];
    int digits;
    if (range.location != NSNotFound) {
        priorityString = [priorityString substringFromIndex:range.location + 1];
        digits = [priorityString length];
    } else {
        range = [priorityString rangeOfString:@"e-"];
        if (range.location != NSNotFound) {
            priorityString = [priorityString substringFromIndex:range.location + 2];
            digits = [priorityString intValue];
        } else {
            digits = 0;
        }
    }

Answer 3

Try this way:

NSString *enteredValue=@"99.1234";

NSArray *array=[enteredValue componentsSeparatedByString:@"."];
NSLog(@"->Count : %ld",[array[1] length]);