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Java Java Objects Delivering the MVP Applying a Discount Code

In the normalizeDiscountCode verify that only letters or the $ character are used. If any other character is used, throw

Hello, What is it wrong why i cant pass ?

private String normalizeDiscountCode(String discountCode){ for(i=0; i<discountCode.length(); i++){ char ch = discountCode.charAt(i); if (! (Character.isLetter(ch)) || ch == '$') ){ throw new IllegalArgumentException("Invalid discount code"); } return discountCode.toUpperCase();

  }
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){
       for(i=0; i<discountCode.length(); i++){
    char ch = discountCode.charAt(i);
    if (! (Character.isLetter(ch)) || ch == '$') ){
        throw new IllegalArgumentException("Invalid discount code");
    }
      return discountCode.toUpperCase();

      }
  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"
    }

  }
}

3 Answers

int i = 0; private String normalizeDiscountCode(String discountCode){ for(i=0; i<discountCode.length(); i++){ char ch = discountCode.charAt(i); if (! (Character.isLetter(ch)) || ch == '$') { throw new IllegalArgumentException("Invalid discount code"); } }

return discountCode.toUpperCase();
 }
Alex Bratkovskij
Alex Bratkovskij
5,329 Points

Hi Araz,

Code logic in general is fine, there are couple of typos:

 private String normalizeDiscountCode(String discountCode){
       for(i=0; i<discountCode.length(); i++){
    char ch = discountCode.charAt(i);
    if (! (Character.isLetter(ch)) || ch == '$')){ // double ' ) '
        throw new IllegalArgumentException("Invalid discount code");
    }
      return discountCode.toUpperCase(); // this goes outside for loop cuz your class should return String, atm it returns nothing

      }

This should be right i mean the return statement should go inside private String normalizeDiscountCode(String discountCode){ but outside for(i=0; i<discountCode.length(); i++){ or ?? if no why ?

int i = 0;

private String normalizeDiscountCode(String discountCode){ for(i=0; i<discountCode.length(); i++){ char ch = discountCode.charAt(i); if (! (Character.isLetter(ch)) || ch == '$') { throw new IllegalArgumentException("Invalid discount code"); } }

return discountCode.toUpperCase();
 }
Bhawani Shankar
Bhawani Shankar
954 Points

char ch = discountCode.charAt(i); what is the use of this statement

Matthew Kaplan
Matthew Kaplan
9,226 Points

private String normalizeDiscountCode(String discountCode) { for (char character : discountCode.toCharArray()) {
if (!Character.isLetter(character) && character != '$') { // note that '$' is between single quotes, since it should be a char, not a string throw new IllegalArgumentException("Invalid discount code."); } } return discountCode.toUpperCase();