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Java Java Objects Delivering the MVP Applying a Discount Code

Basel Kanaan
Basel Kanaan
4,458 Points
Posted by Basel Kanaan
Basel Kanaan
4,458 Points

java.lang.IllegalArgumentException: Invalid discount code. (Look around Order.java line 13)

i still have this issue since i fixed the code , idk what to do to make it run

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

  private String normalizeDiscountCode(String discountCode){
    this.discountCode = discountCode;
    for(char dis : discountCode.toCharArray()) 
    {
      if ( dis == '$' && dis >= 'a' && dis <= 'z')
      { System.out.println("valid discountCode");}
       else 
    { throw new IllegalArgumentException("Invalid discount code.");}
    }
 return this.discountCode.toUpperCase();
  }
  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 = 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"
    }

  }
}

2 Answers

Tlotlo Molokwe
Tlotlo Molokwe
16,618 Points
Tlotlo Molokwe
Tlotlo Molokwe
16,618 Points

try changing your normalizeDiscountCode function to:

private String normalizeDiscountCode(String discountCode){
    for (char letter : discountCode.toCharArray()) {
        if (! Character.isLetter(letter)) {
        if (letter != '$'){
            throw new IllegalArgumentException("Invalid discount code");
        }
      }
    }
 return this.discountCode.toUpperCase();
  }
Fatemah Tavakoli
Fatemah Tavakoli
13,797 Points
Fatemah Tavakoli
Fatemah Tavakoli
13,797 Points

You have almost got this challenge! there are some minor issues only. :)

Task one asks to "Call it from the current applyDiscountCode method and set this.discountCode to the result." you should refer to the discountCode once to avoid confusion. no need for "this.discountCode = discountCode;" 

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

Second task is asking to loop through the discountCode and make sure that there are only letters or '$' character. To solve it we should turn our discountCode string Into array of char and check if it meets the conditions. To get this array we use ".ToCharArray()" method.

Also in normalizeDiscountCode, we dont need "this.discountCode = discountCode;". the task says "It should take the discount code that is passed into the method and return the uppercase version." we achieve this in task one. 

private String normalizeDiscountCode(String discountCode) {
    //looping through the array
    for (char codeChar:discountCode.toCharArray()){
      //checking the conditions
      if ( !Character.isLetter(codeChar) && codeChar != '$'){
        throw new IllegalArgumentException("Invalid discount code"); 
      }
    }
    return discountCode.toUpperCase(); 
  }

Hope it helps! :)