How to loop over Map<String, Array<Any>> in Kotlin?

Question

In my android app with Kotlin, I have a variable "data" type of Map>,Which Product is a kotlin data class.

var data: Map<String, Array<Product>>

Product data class contains var availableQuantities. I want to loop the Map> and conserve only the product with availableQuantities != 0, and update the data variable.How can I do this? Here's my code

   try {
        val filteredMap: HashMap<String, Array<Product>> = HashMap()
        data.forEach { (key, value) ->
            val filtered = value.filter { prod -> prod.availableQuantities != 0 }
            if (filtered.isNotEmpty()) {
                filteredMap[key] = filtered.toTypedArray()
            }
        }
    } catch (e: Throwable) {
        e.message
    }

But, after running the code an exception appear as the following image :

The following image is the description of data :

How can I correct my code to make it functionnal?

When you say your "app is blocked" in various comments below, do you mean that it crashes or that it hangs? — Tenfour04
– Tenfour04, Commented Apr 15, 2020 at 12:48
I add try catch to my code and I get the following exception java.lang.ClassCastException: java.util.ArrayList cannot be cast to com.models.Product[] — Lina
– Lina, Commented Apr 15, 2020 at 12:49

user13319608 · Accepted Answer · 2020-04-15 11:18:35Z

1

I think it could use .values.flatten() to make a flat list.

  val tempProd = data.values.flatten().filter {
            it.availableQuantities != 0
        }

answered Apr 15, 2020 at 11:18

user13319608

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Comments

JensV · Accepted Answer · 2020-04-15 10:52:17Z

0

Wouldn't something like this work?

val tempProd = StreamSupport.stream(data.values.toMutableList())
            .map{t -> t.filter{
                it.availableQuantities!= 0
            } }

You might get empty arrays though, since it's an array of arrays. If you only want a single array, you'd need to reduce the two-dimensional array

answered Apr 15, 2020 at 10:52

JensV

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1 Comment

Lina Over a year ago

No, didn't work I want to loop the data, and update it with only th Product with quantity not zero Did you get me ?

P.Juni · Accepted Answer · 2020-04-15 11:09:15Z

0

Instead of using Stream, you could simply benefit on kotlin extension functions and get rid of empty arrays aswell using flatMap {} in order to merge all arrays of Product to single list.

So Your scenario would look like:

val temp = data.values.flatMap { products ->
    products.filter { product ->
        product.quantity != 0
    }
}

answered Apr 15, 2020 at 11:09

P.Juni

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3 Comments

Lina Over a year ago

When, I use your answer, the app is blocked

P.Juni Over a year ago

what is the message ?

Lina Over a year ago

There's no message, only is blocked even if I debug

IR42 · Accepted Answer · 2020-04-15 11:42:26Z

0

data = data.mapValues { (_, array) ->
    array.filter { it.availableQuantities != 0 }.toTypedArray()
}

answered Apr 15, 2020 at 11:42

IR42

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9 Comments

Lina Over a year ago

I like ur answer, but the app is blocked I don't know why

Lina Over a year ago

It's a dynamic map, it's not statique

IR42 Over a year ago

@Lina at the time when you use this code and the app is blocked. Anyway use it in different thread then

Lina Over a year ago

Yes, When I debug the app, only the message "the application is running" is appear

Lina Over a year ago

I add try catch to my code and I get the following exception java.lang.ClassCastException: java.util.ArrayList cannot be cast to com.models.Product[]

|

SpiritCrusher · Accepted Answer · 2020-04-15 11:51:26Z

0

There are two cases i can think of .If you do not want to keep empty product list against a Key.

val filteredMap: HashMap<String, Array<Product>> = HashMap()
data.forEach { (key, value) ->
    val filtered=value.filter {prod-> prod.availableQuantities!=0 }
    if(filtered.isNotEmpty()){
        filteredMap[key]=filtered.toTypedArray()
    }
 }

Or if you want to keep empty list against a Key then you can try something like :-

val filteredMap= data.mapValues { (_, value) ->
    value.filter { it.availableQuantities != 0 }.toTypedArray()
}

answered Apr 15, 2020 at 11:51

SpiritCrusher

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7 Comments

Lina Over a year ago

I like your answer, thank you But, I don't know why it not work

Lina Over a year ago

the app is blocked even if I debug, I don't know

Lina Over a year ago

I add try catch to my code and I get the following exception java.lang.ClassCastException: java.util.ArrayList cannot be cast to com.models.Product[]

SpiritCrusher Over a year ago

Edit your question with updated code .. i have tested this code it should work efficiently .. If you use Map<String, ArrayList<Product>> instead of Map<String, Array<Product>> things will be a bit easy ..

Lina Over a year ago

We couldn't write a code as the following ? " val tempVariant = StreamSupport.stream(data.toList()) .filter { o1 -> o1.second {it -> } .collect(Collectors.toList<>())"

|

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