Re: Variable Number of Parameters in Method
Re: Variable Number of Parameters in Method
- Subject: Re: Variable Number of Parameters in Method
- From: Alex Zavatone <email@hidden>
- Date: Wed, 21 Aug 2013 14:58:33 -0400
The approach I mentioned is what NSArray uses to allow an arbitrary amount of objects in this call to init it. Supplying nil tells the runtime that there are no more parameters.
NSArray *myArray;
myArray = [NSArray alloc] initWithObjects: @"my String", @"another", @"more", nil];
It's the nil termination of the parameters approach.
How you do this is that bold line that I outlined earlier.
Sent from my iPad
On Aug 21, 2013, at 1:17 PM, "Stephen J. Butler" <email@hidden> wrote:
> On Wed, Aug 21, 2013 at 4:22 AM, Dave <email@hidden> wrote:
>
>> if ([myType isEqualToString:@"NSInteger"] )
>> {
>> myNSInteger = va_arg(myArgumentList,NSInteger*);
>> // do something with myNSInteger
>> [myFormattedString appendFormat:@"myNSInteger = %d ",
>> myNSInteger];
>> }
>>
>> else if ([myType isEqualToString:@"CGFloat"] )
>> {
>> myCGFloat = va_arg(myArgumentList, CGFloat*);
>> // do something with myCGFloat
>> [myFormattedString appendFormat:@"myCGFloat = %f ",
>> myCGFloat];
>> }
>
>
> This is better, however... if you pass an actual NSInteger or CGFloat to
> the method, va_arg() should have a type of NSInteger or CGFloat, not
> pointers to those types. Your code examples with it's printf style formats
> is using the former, not the latter. Just to be clear, you can have all
> these cases:
>
> if ([myType isEqualToString:@"NSInteger"] ) {
> myNSInteger = va_arg(myArgumentList,NSInteger);
> } else if ([myType isEqualToString:@"NSInteger*"] ) {
> pMyNSInteger = va_arg(myArgumentList,NSInteger*);
> } else if ([myType isEqualToString:@"CGFloat"]) {
> myCGFloat = va_arg(myArgumentList, CGFloat);
> } else if ([myType isEqualToString:@"CGFloat*"]) {
> pMyCGFloat = va_arg(myArgumentList, CGFloat*);
> } ... etc
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