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Detecting missing numbers

You want to check if sales from your coffee shop are missing any values, like the sales quantity and amount. Validate a sample sale by checking for nulls.

This exercise is part of the course

Cleaning Data in Java

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Exercise instructions

  • Check if the sale quantity is null.
  • Check if the sale amount is null.
  • Set a default value of 1 for sale quantity if it is null.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

import java.time.LocalDate;

import java.util.Objects;
import java.util.Optional;

public class CoffeeSalesExample {
    private record CoffeeSales(LocalDate date, String coffeeName,
            String paymentMethod, Integer quantity, Double amount) {
    }

    public static void main(String[] args) {
		CoffeeSales sale = new CoffeeSales(LocalDate.of(2024, 3, 1), "Latte", "cash", null, null);

		// Check if the sale quantity is null
        if (Objects.____(sale.____())) {
        	System.out.println("Missing quantity");
        }
    	
        // Check if the sale amount is null
        if (Objects.____(sale.____())) {
        	System.out.println("Missing amount");
        }
    	
        // Set a default value of 1 for sale quantity
        int defaultQuantity = Optional.____(sale.quantity()).____(1);
        System.out.println("Default quantity: " + defaultQuantity);
    }
}
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