Someone can help me ??

Question

Now let's use your validation skills. Only letters and the $ symbols are allowed in the discount code. Check Example.java for use cases

In the normalizeDiscountCode verify that only letters or the $ character are used. If any other character is used, throw a IllegalArgumentException with the message Invalid discount code.

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;
  }
  private String normalizeDiscountCode(String discountCode){


      if ((! discountCode.isLetter(discountCode.length())) || ( discountCode.indexOf(0)!='$')){
             throw new IllegalArgumentException("invalid discount code.");

           }

    return String.toUpperCase(discountCode);
  }

  public String getItemName() {
    return itemName;
  }

  public int getPriceInCents() {
    return priceInCents;
  }

  public String getDiscountCode() {
    return discountCode;
  }

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

  }
}

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 · 2017-03-27T17:15:32Z

March 27, 2017 5:15pm

That's because I thought only one dollar-sign was allowed.

If multiple is allowed, then this should be enough:

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

        return discountCode.toUpperCase();
    }

Answer 2 · 2017-03-27T16:34:52Z

March 27, 2017 4:34pm

The indexOf command looks for a specific character in the string and returns -1 if it is not found.

The argument and expected return value appear to be swapped here.

discountCode.indexOf(0)!='$'

That help?

Answer 3 · 2017-03-27T16:43:18Z

March 27, 2017 4:43pm

A couple of things is wrong here:

You pass length to isLetter like so:

discountCode.isLetter(discountCode.length()))

This will always return false.

Also, You can't just check if the first character is dollar-sign, as it could appear later in the string.

You need to loop through the string and make sure it is all letters or $, and that the dollar sign appear only once.

I haven't tested but this should work:

private String normalizeDiscountCode(String discountCode){
        int numberOfDollarSigns = 0;
        for(char c : discountCode.toCharArray()) {
            if(c == '$') numberOfDollarSigns++;
            if((!Character.isLetter(c) && c != '$') || numberOfDollarSigns > 1) {
                throw new IllegalArgumentException("invalid discount code.");
            }
        }

        return discountCode.toUpperCase();
    }

Answer 4 · 2017-03-27T16:46:30Z

March 27, 2017 4:46pm

Now is better!! ? but the problems is the class String end the return value . This is the errors:

/Order.java:13: error: cannot find symbol if ((! String.isLetter(discountCode.length())) || ( discountCode.indexOf(0)== -1)){ ^ symbol: method isLetter(int) location: class String ./Order.java:18: error: incompatible types: String cannot be converted to Locale return String.toUpperCase(discountCode); ^ Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output 2 errors

Answer 5 · 2017-03-27T17:14:31Z

March 27, 2017 5:14pm

? But there is this error: Bummer! Hmmm...order.applyDiscountCode("$aviNg$") threw an exception, when it shouldn't have

Answer 6 · 2017-11-18T01:27:23Z

November 18, 2017 1:27am

Craig Dennis ~ I appreciate your presence in this answer, so I'm responding here .... as I look at all the different times this question came up in the forum, I keep seeing the similar answer of creating an array and looping through it. However, since we have not yet been introduced to arrays in this Introductory Java track {that will come three video segments later}, I'm wondering if there is a particular way you were expecting us to do it. As I do each of these code challenges, I try to solve them not through external knowledge and googling, but rather through application of the previous video segments instruction {obviously, I know that previous knowledge and Google are important; I just assume that these are designed to be practice of the specific skills just taught}. However, in this case ..... am I missing something? I'm not seeing how to loop through and check for letters or $s just by applying the previous segments' lessons.

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Sara Pasinato

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Someone can help me ??

6 Answers

Thomas Nilsen

Thomas Nilsen

Sara Pasinato

Sara Pasinato

Craig Dennis

Craig Dennis

Thomas Nilsen

Thomas Nilsen

Sara Pasinato

Sara Pasinato

Cody Rikard

Cody Rikard

Sara Pasinato

Sara Pasinato

Thomas Nilsen

Thomas Nilsen

Sara Pasinato

Sara Pasinato

Stephanie Youstra

Stephanie Youstra

Stephanie Youstra

Stephanie Youstra

Craig Dennis

Craig Dennis