How will I be able to remove [NSNull Null] objects from NSMutableArray?

问题

I need to remove Null object added by

 [mutArrSkills addObject:[NSNull null]];

Do I need to iterate? Is there any function to remove all null values from NSMutableArray?

If need to Iterate, how will I do that?

回答1:

You can use NSMutableArray's removeObjectIdenticalTo: method, as follows

[mutArrSkills removeObjectIdenticalTo:[NSNull null]];

to remove the null values. No need to iterate.

回答2:

removeObjectIdenticalTo:

Removes all occurrences of a given object in the array.

Discussion This method uses the indexOfObjectIdenticalTo: method to locate matches and then removes them by using removeObjectAtIndex:. Thus, matches are determined using object addresses. If the array does not contain anObject, the method has no effect (although it does incur the overhead of searching the contents).

回答3:

You can try doing this,

NSNull *nullValue = [NSNull null]; 

[mutArrSkills removeObjectIdenticalTo:nullValue];

I hope this helps.

回答4:

In Swift you first have to cast your Swift Array to NSArray, make and make it mutable so you can remove the Objective-C leftover elements, then cast it back to Array.

Fatal error: NSArray element failed to match the Swift Array Element type

// my crashing array, containing a not String element, like NSNull or anything else
let myUnsafeSwiftArray: [String]

// make it safely NSArray, then make it mutable
let mutableUnsafeArray = NSMutableArray(array: myUnsafeSwiftArray as NSArray)

// remove leftover class, like [NSNull null] aka NSNull.init()
unsafeTextures.removeObject(identicalTo: NSNull.init())

// Cast the safe array back to its supposed to by element type
let safeArray = unsafeTextures as? [String]

回答5:

You may iterate like this.

for(int i=0,i<[mutArrSkills count]; i++)
{
  if([[mutArrSkills objectAtIndex:i] isKindOfClass:[NSNull Class]])
    {
    [mutArrSkills removeObjectAtIndex:i];  
   }
}

来源：https://stackoverflow.com/questions/9192301/how-will-i-be-able-to-remove-nsnull-null-objects-from-nsmutablearray

标签

iphone

objective-c

ios4

nsmutablearray