Making an array of integers in iOS
C array:
NSInteger array[6] = {1, 2, 3, 4, 5, 6};
Objective-C Array:
NSArray *array = @[@1, @2, @3, @4, @5, @6];
// numeric values must in that case be wrapped into NSNumbers
Swift Array:
var array = [1, 2, 3, 4, 5, 6]
This is correct too:
var array = Array(1...10)
NB: arrays are strongly typed in Swift; in that case, the compiler infers from the content that the array is an array of integers. You could use this explicit-type syntax, too:
var array: [Int] = [1, 2, 3, 4, 5, 6]
If you wanted an array of Doubles, you would use :
var array = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0] // implicit type-inference
or:
var array: [Double] = [1, 2, 3, 4, 5, 6] // explicit type
You can use a plain old C array:
NSInteger myIntegers[40];
for (NSInteger i = 0; i < 40; i++)
myIntegers[i] = i;
// to get one of them
NSLog (@"The 4th integer is: %d", myIntegers[3]);
Or, you can use an NSArray
or NSMutableArray
, but here you will need to wrap up each integer inside an NSNumber
instance (because NSArray
objects are designed to hold class instances).
NSMutableArray *myIntegers = [NSMutableArray array];
for (NSInteger i = 0; i < 40; i++)
[myIntegers addObject:[NSNumber numberWithInteger:i]];
// to get one of them
NSLog (@"The 4th integer is: %@", [myIntegers objectAtIndex:3]);
// or
NSLog (@"The 4th integer is: %d", [[myIntegers objectAtIndex:3] integerValue]);
If you want to use a NSArray, you need an Objective-C class to put in it - hence the NSNumber requirement.
That said, Obj-C is still C, so you can use regular C arrays and hold regular ints instead of NSNumbers if you need to.
You can use CFArray instead of NSArray. Here is an article explaining how.
CFMutableArrayRef ar = CFArrayCreateMutable(NULL, 0, NULL);
for (NSUInteger i = 0; i < 1000; i++)
{
CFArrayAppendValue(ar, (void*)i);
}
CFRelease(ar); /* Releasing the array */
The same applies for the CoreFoundation version of the other containers too.