Can not write code to throw exception for strings containing $.

Question

I've written code to not throw an exception when the discount code contains letters but not when it contains "$"

Order.java

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

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

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 · 2017-01-16T17:02:44Z

January 16, 2017 5:02pm

Try this, it's much simpler:

private String normalizeDiscountCode(String discountCode) {
    if discountCode.contains("$") {
        throw new IllegalArgumentException("Invalid discount code.%n");
    }
    return discountCode.toUppercase();
}

All it's doing is it takes in a argument and in the argument contains "$" then raise an error. If all goes well, just return the uppercased version of the argument.

I hope this helps. ~Alex

Answer 2 · 2017-01-16T17:05:31Z

January 16, 2017 5:05pm

Hello Carlo,

Now at the current stage it looks OK, now we're missing jsut one small detail. IF (discountCode does not consist of letters OR discountCode doesnt start with '$' we will throw an exception at users.

Do u need help with code itself, or whats stopping you from writing a code?

-Alex

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Carlo Antonio Bilbao

Carlo Antonio Bilbao

Can not write code to throw exception for strings containing $.

2 Answers

Alexander Davison

Alexander Davison

Carlo Antonio Bilbao

Carlo Antonio Bilbao

Alex Bratkovskij

Alex Bratkovskij