NSMutableArrays仅存储2个对象

Question

I have a weird problem - my mutable array stores only 2 objects - its count is 1,2,2,2 and doesn't change. My only observation is that it always replaces old values fx I have: value1 - 2, value2 - 4 and I add next object fx 66 and my array look like this: value1 - 4, value2 - 66. Here is some code:

func appendArrays(product: NSString, bPrice: NSString, sPrice: NSString) {
    defaults.synchronize()
    if prodArr.count == 0 {
        prodArr = NSMutableArray(array: [defaults.valueForKey(keys.keyProduct)!])
        bpArr   = NSMutableArray(array: [defaults.valueForKey(keys.keyBPrice)!])
        spArr   = NSMutableArray(array: [defaults.valueForKey(keys.keySPrice)!])
    }

    prodArr.addObject(product)
    bpArr.addObject(bPrice)
    spArr.addObject(sPrice)

    defaults.setObject(prodArr, forKey: keys.keyProduct)
    defaults.setObject(bpArr, forKey: keys.keyBPrice)
    defaults.setObject(spArr, forKey: keys.keySPrice)

    defaults.synchronize()
    NSLog("%i",[defaults.valueForKey(keys.keyBPrice)!].count)
}

Answer 1

This is occurring because you're declaring the arrays inside the scope of the function, thus they get destroyed each time you call the method.

Instead declare them at the top of your swift file, just after the Class name, so that they are properties.

Answer 2

Of course you can have not more than two objects because your spArr is declared locally and it means that you create a new spArr object each time you call appendArrays . You need to create it var spArr: NSMutableArray = NSMutableArray() outside the function and instead of doing:

spArr   = NSMutableArray(array: [defaults.valueForKey(keys.keySPrice)!])

do

spArr.addObject([defaults.valueForKey(keys.keySPrice)!])