CODEWITHSUNDEEP
objective-cconditional-statements
Js Lim
Js Lim

Reputation: 3675

Objective C: -1 < 0 return false

Is there any difference between this 2?

int count = 0;
for (UIView *view in scrollView.subviews) {
    NSLog(@"%d < %d", [json[@"images"] count] - 1, count);
    // Output: -1 < 0
    if ([json[@"images"] count] - 1 < count) break;
}

and

int count = 0, maxIndex = [json[@"images"] count] - 1;
for (UIView *view in scrollView.subviews) {
    NSLog(@"%d < %d", maxIndex, count);
    // Output: -1 < 0
    if (maxIndex < count) break;
}

What I've facing just now was, the first solution didn't break the loop, whereas the second solution did.

Is there any reason behind?

Upvotes: 0

Views: 62

Answers (1)

Sarim Sidd
Sarim Sidd

Reputation: 2176

Thats because count is NSUInteger property. Therefore it will never be -1 in your case.And in your second case you're assigning maxIndex to int, which then gives you -1.

So try this to clearly understand whats happening.

int count = 0;
NSUInteger maxIndex = [json[@"images"] count] - 1;
for (UIView *view in scrollView.subviews) {
NSLog(@"%d < %d", maxIndex, count);
// Output: -1 < 0
if (maxIndex < count) break;  //This will not break either as maxIndex will never be `-1`

}

Also,in your NSLog your using %d which is format specifier for type int , try %lu or %lx

Hope this helps

Upvotes: 3

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