I don't understand what's wrog with my code ?

Question

I've seen that other people are solving the problem with a For Statement and I don't understand why and I don't understand a lot of what it says in their code like this one: for(i=0; i<discountCode.length(); i++){ char ch = discountCode.charAt(i); if (! (Character.isLetter(ch)) || ch == '$')){ // double ' ) ' throw new IllegalArgumentException("Invalid discount code") I mean I could just copy this and that's it, but I want to understand why am I understanding a different instruction or what am I not understanding. Could somebody help me with this ?

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) {
      if (! Character.isLetter  (letter | $)) {
      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 · 2019-02-16T10:00:27Z

February 16, 2019 10:00am

normalizeDiscountCode method is not implemented in a right way

  private String normalizeDiscountCode(String discountCode){
    for(char letter: discountCode.toCharArray()){
        if(!Character.isLetter(letter) && letter != 36){
         throw new IllegalArgumentException("Invalid discount code.");
        }
    }       
    return discountCode.toUpperCase();      
  }

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Sebastian García

Sebastian García

I don't understand what's wrog with my code ?

1 Answer

Marie Franklin

Marie Franklin