CODEWITHSUNDEEP
if-statementpipeline
Aleksander Azizi
Aleksander Azizi

Reputation: 9877

if "or pipes" (||) bug?

I'm looping through my view's subviews (with a total of 10 subviews).

Before doing so, I declare a new int to be used as a counter.

I'm checking if the count isn't equal to a hard-coded value (!=):

int count = 0;

for (UIView *subview in self.view.subviews) {
    count = count + 1;

    if (count != 5) {
        NSLog(@"Hello");
    } else {
        NSLog(@"World");
    }
}

With this, NSLog(@"World"); is invoked when the count is equal to "5" (as expected):

Hello Hello Hello Hello World Hello Hello Hello Hello Hello Hello Hello

Now to the issue, if I add "or pipes" (||), NSLog(@"World"); is never invoked (if isn't validated).

int count = 0;

for (UIView *subview in self.view.subviews) {
    count = count + 1;

    if (count != 5 || count != 6) {
        NSLog(@"Hello");
    } else {
        NSLog(@"World");
    }
}

Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello

Now this issue can ofc be fixed by changing the syntax, but my question is why isn't the if validated?

It should be noted, that changing the "not equal" (!=) to "is equal" (==) solves the issue.

Is this a bug, or have I missed something?

Upvotes: 0

Views: 35

Answers (1)

mipadi
mipadi

Reputation: 410622

Your conditional is always true. Given count != 5 || count != 6, if count == 5 then the latter half is true; if count == 6 then the former half is true; and if count equals anything else, the statement is also true.

You may have meant to use && instead.

Upvotes: 3

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