objective-C algorithm obstacle

Question

This piece of code is inside shake event's scope,

if(i % 3) {
    self.Label.text = [NSString stringWithFormat:@"%d", y];
    y += 1;        
}

whenever i reaches 3,
y += 1 executes.

When I shake it again,

y value adds another 1
i is now equal to 4

So now i = 4 and y = 2, I get the idea why y is adding another 1 but I just can't figure out how to avoid it, please help.

You should try to learn basic programming, the most basic about the what operators are doing will help you already. — alinoz, Jan 30 '14 at 13:06
possible duplicate of [How Does Modulus Divison Work](http://stackoverflow.com/questions/2664301/how-does-modulus-divison-work) — Mick MacCallum, Jan 30 '14 at 13:08
I am really sorry @alinoz for being new and just trying to ask question and learn. — shaideru, Jan 30 '14 at 13:22
@frustratediOS developer before asking questions you should invest a minimum effort for understanding what are you doing. no body can just put the knowledge directly in your head. There are some steps that can not be bypassed. — alinoz, Jan 30 '14 at 15:05

score 6 · Answer 1 · answered Jan 30 '14 at 13:05

6

Try if (i % 3 == 0). By using i % 3, the piece of code will execute whenever i is not divisible by 3 rather than only when i is divisible by 3.

answered Jan 30 '14 at 13:05

JAB

20,783
6
71
80

score 1 · Accepted Answer · answered Jan 30 '14 at 13:04

1

Probably you are looking for this:

if(i % 3  == 0){

        self.Label.text = [NSString stringWithFormat:@"%d", y];
        y += 1;        
}

This code will increase y only every 3rd iteration (or shake or whatever you are doing)

answered Jan 30 '14 at 13:04

Oleg Fedorov

337
3
10

That did it! thank you so much! I changed the 0 to 1 though :) – shaideru Jan 30 '14 at 13:24
@frustratediOSdeveloper That will cause the code to execute when `i-1` is divisible by 3. It will still occur only once every three times, but there will be a shift in when the execution occurs. (Which may be desired behavior if `i` starts at 0 before any shakes, increases by 1 for each shake, and you want `y+=1` to start with the first shake rather than the third, I suppose.) – JAB Jan 30 '14 at 14:27

score 0 · Answer 3 · answered Jan 30 '14 at 13:26

The correct way can you try this:

if(i % 3 == 0) {
    NSLog(@"Value of i : %d and Y is : %@", i, [NSString stringWithFormat:@"%d", y]);
    self.Label.text = [NSString stringWithFormat:@"%d", y];
    y += 1;        
} else {
    NSLog(@"Value of i : %d and Y is : %@", i, [NSString stringWithFormat:@"%d", y]);
}

objective-C algorithm obstacle

3 Answers3