iOS Switch Case

[nickculbertson]

Hello,
I think this should be an easy question for most but I'm having trouble finding the answer. I know how to switch between cases using rand and arcrand but how do I switch them in order 1,2,1,2,1,2,1,2...

// for random
int Number = rand() % 2;
switch (Number){
		case 0:{
                         NSLog(@"one");}
			break;
		case 1:{
			NSLog(@"two");}
			break;
		default:
			break;
	}	
	
}

// for non random

int Number = //How do I just make this = 2
switch (Number){
		case 0:{
                         NSLog(@"one");}
			break;
		case 1:{
			NSLog(@"two");}
			break;
		default:
			break;
	}	
	
}

thanks,
Nick

 

[Luke Redpath]

I'd love to help, but I have absolutely no idea what you're trying to achieve.

 

[ulbador]

XOR it:

int Number = 1;
Number = Number ^ 1; // i is now 0
Number = Number ^ 1; // i is now 1
Number = Number ^ 1; // i is now 0

 

[seepel]

XOR it:

int Number = 1;
Number = Number ^ 1; // i is now 0
Number = Number ^ 1; // i is now 1
Number = Number ^ 1; // i is now 0

This sounds a lot better than my solution, but I'll post mine anyway, just in case someone wants to have a higher sequence, for example 0,1,2. And of course number_ is an iVar or global variable, something that is going to stick around.

#define SEQUENCE_COUNT 3
number_++;
switch(number_ % SEQUENCE_COUNT) {
    case 0:
        // Do some stuff
        break;
    case 1:
        // Do some stuff
        break;
    case 2:
        // Do some stuff
        break;
    default:
       // Shouldn't ever get here!
       break;
}

 

[balamw]

XOR it:

In this case, NOT would be just fine, no?

int number = 0;
number = !number; //1
number = !number; //0
number = !number; //1

I know many of you don't like seeing seemingly boolean operators as integers...

(EDIT: I was going to add something about mod, but seepel got to it first.)

B

 

[ulbador]

In this case, NOT would be just fine, no?

I think using ! is probably better.

You can look at that and know exactly what it's doing quickly, versus using XOR and having to think about your bitwise math. The modulo operation is definitely good too for the reasons mentioned (ability to two more than just 2 numbers).

 

[PhoneyDeveloper]

And for completeness, if you need to oscillate between two values that don't happen to be 0 and 1 you can do it like this

#define kValue1 27 // or whatever
#define kValue2 42  // or whatever

// Setup
int currentValue = kValue1;

// Oscillate
currentValue = (kValue1 + kValue2) - currentValue;

Obviously that code also works with values of 0 and 1 but using a boolean and currentValue = ! currentValue is more idiomatic for that case.

 

[nickculbertson]

Thanks for your help guys. This did the trick.

static int Number = 0;
Number ^= 1;
	
	
	switch (Number){

Thanks,
Nick