CODEWITHSUNDEEP
objective-cnsarray
Alessandro
Alessandro

Reputation: 4100

Shortening code to add a variable number of objects to an NSMutableArray

Is there a way to shorten this code?

NSMutableArray *allobjects = [[NSMutableArray alloc] initWithCapacity:b];

    if (b == 1) {
        [allobjects addObject:object];
    }else if (b == 2){
        [allobjects addObject:object];   
        [allobjects addObject:object2];
    }else if (b == 3){

        [allobjects addObject:object];
        [allobjects addObject:object2];
        [allobjects addObject:object3];
    }else if (b == 4){

        [allobjects addObject:object];
        [allobjects addObject:object2];
        [allobjects addObject:object3];
        [allobjects addObject:object4];

    }else if (b == 5){

        [allobjects addObject:object];
        [allobjects addObject:object2];
        [allobjects addObject:object3];
        [allobjects addObject:object4];
        [allobjects addObject:object5];
    }else if (b == 6){

        [allobjects addObject:object];
        [allobjects addObject:object2];
        [allobjects addObject:object3];
        [allobjects addObject:object4];
        [allobjects addObject:object5];
        [allobjects addObject:object6];
    }else if (b == 7){

        [allobjects addObject:object];
        [allobjects addObject:object2];
        [allobjects addObject:object3];
        [allobjects addObject:object4];
        [allobjects addObject:object5];
        [allobjects addObject:object6];
        [allobjects addObject:object7];
    }else if (b == 8){

        [allobjects addObject:object];
        [allobjects addObject:object2];
        [allobjects addObject:object3];
        [allobjects addObject:object4];
        [allobjects addObject:object5];
        [allobjects addObject:object6];
        [allobjects addObject:object7];
        [allobjects addObject:object8];
    }

As you can see, if b equals 1 I add object1, if b is 2, I add both object1 and object2, and so on.

Upvotes: 0

Views: 107

Answers (5)

Hot Licks
Hot Licks

Reputation: 47699

Sigh!

switch (b) {
    case 8 :
        [allobjects insertObject:object8 atIndex:0];
    case 7 :
        [allobjects insertObject:object7 atIndex:0];
    case 6 : 
        [allobjects insertObject:object6 atIndex:0];
    case 5 :
        [allobjects insertObject:object5 atIndex:0];
    case 4 :
        [allobjects insertObject:object4 atIndex:0];
    case 3 :
        [allobjects insertObject:object3 atIndex:0];
    case 2 :
        [allobjects insertObject:object2 atIndex:0];
    case 1 :
        [allobjects insertObject:object atIndex:0];
        break;
    default :
        <Signal error or whatever>
}

If the entries don't need to be in order you can just use addObject.

You can also use a variation on the OP's original code:

if (b >= 1) [allobjects addObject:object];
if (b >= 2) [allobjects addObject:object2];
if (b >= 3) [allobjects addObject:object3];
if (b >= 4) [allobjects addObject:object4];
if (b >= 5) [allobjects addObject:object5];
if (b >= 6) [allobjects addObject:object6];
if (b >= 7) [allobjects addObject:object7];
if (b >= 8) [allobjects addObject:object8];

Upvotes: 1

deanWombourne
deanWombourne

Reputation: 38475

Here's two alternative answers :

1.

What about doing it dynamically (assuming you can rename object to object0 to fit the pattern!)

for (uint n = 0; n < b; ++n) {
    NSString *name = [NSString stringWithFormat:@"object%i], n];
    [allObjects addObject:[self performSelector:name]];
}

However, this is slower at runtime than the other array based answers (you have to make a new string each time wheras their arrays can be made in viewDidLoad).

2.

Another way would be to use the tag property of a view - then your loop would become something like :

for (uint n = 0; n < b; ++n) 
    [allObjects addObject:[self.view viewWithTag:n]];

Upvotes: 1

jscs
jscs

Reputation: 64002

Put all those strings into a C array:

NSString * objects[] = { object1, object2, object3, object4, object5, object6, object7, object8, object9 };

Then iterate over that once you know what b's value is: 

allObjects = [NSMutableArray array];
for( int i = 0; i < b; i++ ){
    [allObjects addObject:objects[i]];
}

Or, even better, do:

allObjects = [NSMutableArray arrayWithObjects:objects count:b];

Upvotes: 3

Nathan Kinsinger
Nathan Kinsinger

Reputation: 25011

NSArray *allStrings = [NSArray arrayWithObjects:object, object2, object3, object4, object5, object6, object7, object8, object9, nil];

NSArray *objects = nil;
if (b <= [allStrings count])
    objects = [allStrings subarrayWithRange:NSMakeRange(0, b)];

Upvotes: 1

sha
sha

Reputation: 17860

NSString* ojbs[] = { object1, object2, object3, object4, object5, object6, object7, object8, object9 };

int _count = 5; // for example

NSArray* arr = [NSArray arrayWithObjects: objs count: _count];
NSMutableArray* result = [NSMutableArray arrayWithCapacity: _count];
[resul addObjectsFromArray: arr];

Upvotes: 1

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