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androidkotlinsparse-matrix

Best way to sum all values of a SparseIntArray

What is the best way to sum all the values of a SparseIntArray in Kotlin ?

I try something but it's not working... This is my code (quantities is the SparseIntArray) :

var amount = 0
for (q in quantities){
     amount += q
}

But I have this error :

For loop range must have an 'iterator()' method

Be careful : my problem don't concern ArrayList but SparseIntArray.

Solution

  • You need to do this manually:

    var amount = 0
for (i in 0 until quantities.size()) {
    amount += quantities.valueAt(i)
}

    If you use android-ktx, you can also rewrite this as:

    var amount = 0
quantities.forEach { k, v -> amount += v }