How to get max double in list?? With only one output, using Kotlin - kotlin

Question

I have tried using .maxBy .max() and collection.Max and I have only been able to print with it stating every element is max
val fileName = "src/products.txt"
var products = HashMap<Int, Pair<String, Double>>()
var inputFD = File(fileName).forEachLine {
var pieces = it.split(",")
println("Item# Description Price")
println("----- ------------- ------")
for ( (pro,ducts) in products.toSortedMap() ) {
var pax = mutableListOf(ducts).maxBy { it -> it.second }
var highest = listOf<Double>(ducts.second).max()
println("The highest priced record is ${highest}")
}
the file is set up like this (111, shoe, 9.99)
output looks like this
The highest priced record is [(pants, 89.99)]
The highest priced record is [(shoes, 49.99)]

Answer 1

You are trying to print the value within the for-loop, hence it is printing it for every product. Also the variable is initialized everytime in the loop, so every value would be max.
Here is the right approach. Note that you can solve it without using mutable variables.
val fileName = "src/products.txt"
val products = File(fileName).readLines() //read all lines from file to a list
.map { it.split(",") } // map it to list of list of strings split by comma
.map { it[0] to it[1].toDouble() } // map each product to its double value in a Pair
.toMap() // convert list of Pairs to a Map
println("Item# Description Price")
println("----- ------------- ------")
products.keys.forEachIndexed { index, desc ->
println("$index\t$desc\t${products[desc]}")
}
println("The highest priced record is ${products.maxBy { it.value }}")