Code is not throwing exception

Question

This has been driving me crazy for the past week. From what I can see, the code should throw an exception if the submitted discount code contains anything other than a letter or $.

So the question is, what am I missing?

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) {
    try {
      this.discountCode = normalizeDiscountCode(discountCode);
    }catch(IllegalArgumentException e) {
      System.out.println(e.getMessage());
    }

  }

  private String normalizeDiscountCode(String discountCode) {

    for(char temp : discountCode.toCharArray()) {
      if(Character.isLetter(temp)) {

      } else {
        if(temp != '$') {
          throw new IllegalArgumentException("Invalid discount code.");
        }
      }
    }
    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 · 2017-05-01T00:18:49Z

May 1, 2017 12:18am

While your if statement is somewhat on the messy side you are correct that it will in fact work for this challenge. The issue is actually not in your normalizeDiscountCode method but in your applyDiscountCode method.

The challenge asks you to throw an exception but never tells you to setup code to catch it, and in fact doing so will break the challenge. If you catch the exception with your own code then it won't reach the challenge checker that runs your code to verify its behavior.

If you remove the try/catch block from the applyDiscountCode method like this:

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

Then your code will work.

Also for future reference, nesting if statements like you have done is rarely the optimal way of checking multiple conditions, using the || or && operator will in most cases be shorter and easier to read. For this task for example the if statement can be as simple as this:

if(!Character.isLetter(temp) && temp != '$') {
    throw new IllegalArgumentException("Invalid discount code.");
}

The above condition basically states "If temp is NOT a character AND temp is NOT EQUAL to $ then run the code". It has the same effect as the if/else/if statement you have written in your solution.

Answer 2 · 2017-05-01T17:42:53Z

May 1, 2017 5:42pm

Thanks for the help.

The nested for business is actually from my trying to figure out why it wasn't throwing the exception.

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James Dunn

James Dunn

Code is not throwing exception

2 Answers

andren

andren

James Dunn

James Dunn