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LESSON 165 OF 414 · PROJECTS: EVERYDAY PROGRAMS

Shopping Cart V4 - Cart Sum in Kotlin

Practice

Use a for loop over parallel arrays to compute a running total across several items.

You start with:

        val items = arrayOf("Shirt", "Pants", "Shoes", "Hat")
        val prices = intArrayOf(25, 40, 60, 15)
        val quantities = intArrayOf(2, 1, 1, 3)

Build:

Shirt x2: $50
Pants x1: $40
Shoes x1: $60
Hat x3: $45
Total: $195

Rules:

  • For each index i, the item's subtotal is prices[i] * quantities[i].
  • Build one line per item, in order, in the format "Name xQ: $subtotal" (e.g. "Shirt x2: $50").
  • Add every subtotal to a running total.
  • Finish with a "Total: $..." line.
  • Join all the lines with a newline "\n" into one string result, then print it with println(result).

Use val lines = mutableListOf<String>() and var total = 0 before the loop, then add each formatted line.

Call lines.joinToString("\n") at the end.

        val items = arrayOf("Shirt", "Pants", "Shoes", "Hat")
        val prices = intArrayOf(25, 40, 60, 15)
        val quantities = intArrayOf(2, 1, 1, 3)

        val lines = mutableListOf<String>()
        var total = 0
        for (i in items.indices) {
            val sub = prices[i] * quantities[i]
            total = total + sub
            lines.add(items[i] + " x" + quantities[i] + ": $" + sub)
        }
        lines.add("Total: $" + total)
        val result = lines.joinToString("\n")
        println(result)

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    Shopping Cart V4 in Kotlin

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