In the normalizeDiscountCode verify that only letters or the $ character are used. If any other character is used,

Question

I am confused on what I need to do on this section to complete it.

Order.java

public class Order {
  private String itemName;
  private int priceInCents;
  private String discountCode;

  public Order(String itemName, int priceInCents) {
    this.itemName = itemName;
    this.priceInCents = priceInCents;
  }

  public String getItemName() {
    return itemName;
  }

  public int getPriceInCents() {
    return priceInCents;
  }

  public String getDiscountCode() {
    return discountCode;
  }

  public void applyDiscountCode(String discountCode) {
    this.discountCode = normalizeDiscountCode(discountCode);
  }


  private String normalizeDiscountCode(String discountCode) {
    return discountCode.toUpperCase();
}
}

Example.java

public class Example {

  public static void main(String[] args) {
    // This is here just for example use cases.

    Order order = new Order(
            "Yoda PEZ Dispenser",
            600);

    // These are valid.  They are letters and the $ character only
    order.applyDiscountCode("abc");
    order.getDiscountCode(); // ABC

    order.applyDiscountCode("$ale");
    order.getDiscountCode(); // $ALE


    try {
      // This will throw an exception because it contains numbers
      order.applyDiscountCode("ABC123");
    } catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());  // Prints "Invalid discount code"
    }
    try {
      // This will throw as well, because it contains a symbol.
      order.applyDiscountCode("w@w");
    }catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());  // Prints "Invalid discount code"
    }

  }
}

Answer 1 · 2018-05-01T09:40:16Z

May 1, 2018 9:40am

Hi, I've been asked to answer this question.

So, here goes:

We are creating a for each loop which will loop over every character in the discountCode string inside normalizeDiscountCode method. We do this by using the toCharArray() method which will create an array of all the chars of the passed in discountCode parameter. We'll loop over this array.

Inside the loop, for every character we then check if the character is a letter or the symbol $. If that turns out to be false (notice the ! sign before the whole expression), we throw a new IllegalArgumentException with the requested message.

If all the characters are actually letters or the symbol $ that exception never gets raised and the method completes the usual way and returns the discountCode uppercased as in the Task 1 of the challenge.

This is the code:

  private String normalizeDiscountCode(String discountCode) {
    for (char c : discountCode.toCharArray()) {
      if (!(Character.isLetter(c) || c == '$')) {
        throw new IllegalArgumentException("Invalid discount code");
      }
    }
    return discountCode.toUpperCase();
  }

Hope it helps.

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Eric Gentry

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In the normalizeDiscountCode verify that only letters or the $ character are used. If any other character is used,

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