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Java Java Objects Delivering the MVP Applying a Discount Code

Rikki MCguire
Rikki MCguire
2,232 Points

normalize $ sign

I have tried this code in workspace. When i run anything with the $ at the end returns uppercase all ok eg ad$ returns AD$. if i did a1$ it throws exception for 1.

If i send int $ in the middle eg e$1 it doesnt throw and exception but returns E. and if the $ is at the front $eg i get: ArrayIndexOutOfBounds..

WTH is going on been trying for 4 days now....

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){




     for (char letter : discountCode.toUpperCase().toCharArray()){
  if (!Character.isLetter(letter) && letter != '$'){
      throw new IllegalArgumentException("Invalid discount code"); 
  }

}

    return discountCode.toUpperCase();

  }


  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 iae){
System.out.printf(iae.getMessage());
}


  }
}
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"
    }

  }
}
Amrit Pandey
Amrit Pandey
17,595 Points

I cannot understand fully what you want to achieve but lets examine you code.

  private String normalizeDiscountCode(String discountCode){




     for (char letter : discountCode.toUpperCase().toCharArray()){
  if (!Character.isLetter(letter) && letter != '$'){
      throw new IllegalArgumentException("Invalid discount code"); 
  }

}

    return discountCode.toUpperCase();

  }

Few pitfalls that you created,

  1. You see, you have used .toUpperCase twice in you code, since we want uppercase discount code already why not do it first.
  2. Regular expressions are used to examine and decipher Strings, I can not provide you with the pattern since I don't know much about it, check out the video, Craig tells about it.
  3. You are using IllegalArgumentException like System.Out.print !, which is wrong.

I am just correcting your function, It have nothing to do with the code challenge, please watch video for that.

 private String normalizeDiscountCode(String discountCode){

discountCode = discountCode.toUppercase();

     for (char letter : discountCode.toCharArray()){
        if (!Character.isLetter(letter) && letter != '$'){
          throw new IllegalArgumentException("Invalid discount code", iae); 
          System.out.println(iae.getMessage());
        }
   }

    return discountCode;

  }

1 Answer

Rikki MCguire
Rikki MCguire
2,232 Points

I added toUpperCase() at the end as the code challenge was saying it wasnt returning so i tried that. and as for IllegalArgumentException you are wrong that is the incorrect format. iae is specified in the try catch statement not in the throw statement.

Here it is on the oracle website;

IllegalArgumentException() Constructs an IllegalArgumentException with no detail message. IllegalArgumentException(String s) Constructs an IllegalArgumentException with the specified detail message. IllegalArgumentException(String message, Throwable cause) Constructs a new exception with the specified detail message and cause.