If statement failing to pass while using string matches

Question

Im sure my if statement is wrong but I have been looking at it for hours now and I just can figure it out.

Order.java

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

 private String normalizeDiscountCode(String discountCode) {
   if (! discountCode.matches("[^A-Za-z]+$")) {
     throw new IllegalArgumentException("Invalid discount code");
   }
   discountCode = discountCode.toUpperCase();
   return 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 · 2017-01-24T14:46:26Z

January 24, 2017 2:46pm

Hi Reagan, just two small issues, you are calling the match method on a variable that doesn't exist, and your regular expression needs fixing too :)

^[A-Za-z$]+$ looks for anything that is either a alphabetic character or a dollar sign. The ^ must be at the front of the pattern, and not inside the square brackets (where it has a completely different meaning).

private String normalizeDiscountCode(String code) {
  if (!code.matches("^[A-Za-z$]+$")) {  // make sure you are calling the match method on the code variable
     throw new IllegalArgumentException("Invalid discount code");
  }
  return code.toUpperCase(); 
}

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Reagan Govender

Reagan Govender

If statement failing to pass while using string matches

1 Answer

Umesh Ravji

Umesh Ravji