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Java Java Objects Delivering the MVP Applying a Discount Code

Remco de Wilde
Remco de Wilde
9,864 Points

What am i doing wrong? normalize Discount Code in Java Objects

Don't understand this, I check for letter and $.

Hmmm...I ran order.applyDiscountCode("h1!") and I expected it to throw an IllegalArgumentExcept

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){
  this.discountCode=discountCode.toUpperCase();

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

  public String getItemName() {
    return itemName;
  }

  public int getPriceInCents() {
    return priceInCents;
  }

  public String getDiscountCode() {
    return discountCode;
  }

  public void applyDiscountCode(String discountCode) {
    try{
    discountCode=normalizeDiscountCode(discountCode) ;
    }catch (IllegalArgumentException iae){
    //do something
    }
  }
}
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"
    }

  }
}

3 Answers

Remco de Wilde
Remco de Wilde
9,864 Points

Changed code to my first version always throws exception because !$ is always true as long as there is no $:

private String normalizeDiscountCode (String discountCode){
  this.discountCode=discountCode.toUpperCase();

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

first run

h gives ! letter = false and not $ true no exeption

Second run

1 gives ! letter = true and not $ true must give exexption so what is wrong with my reasoning.

Wagner Melo
Wagner Melo
2,121 Points

Tks Remco, I was also using ||

Remco de Wilde
Remco de Wilde
9,864 Points

The problem was the try, catch, removing them solved the problem, i did this some days ago, but forgot to post the solution here.

Arcee Palabrica
Arcee Palabrica
8,100 Points

Your code seems fine... my question though is in your applyDiscountCode() method... Your try-catch block is already in the example.java file.