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Java Java Objects Delivering the MVP Applying a Discount Code

Rikki MCguire
Rikki MCguire
2,232 Points

unexpected type

private String normalizeDiscountCode(String code){ String alphabet = "abcdefghijklmnopqrstuvwxyz$";

for (char letter : code.toCharArray();){

if (alphabet.indexOf(letter) = -1){ throw new IllegalArgumentException("Invalid discount Code"); }


get error:

./Order.java:15: error: unexpected type if (alphabet.indexOf(letter) = -1){ ^ required: variable found: value Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 1 error

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 code){
 String alphabet = "abcdefghijklmnopqrstuvwxyz$";
    char[] codes = code.toCharArray();

    for (char letter : codes){
  if (alphabet.indexOf(letter) = -1){
   throw new IllegalArgumentException("Invalid discount Code"); 


    return code.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);
public class Example {

  public static void main(String[] args) {
    // This is here just for example use cases.

    Order order = new Order(
            "Yoda PEZ Dispenser",

    // These are valid.  They are letters and the $ character only
    order.getDiscountCode(); // ABC

    order.getDiscountCode(); // $ALE

    try {
      // This will throw an exception because it contains numbers
    } catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());  // Prints "Invalid discount code"
    try {
      // This will throw as well, because it contains a symbol.
    }catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());  // Prints "Invalid discount code"


1 Answer

Wout Ceulemans
Wout Ceulemans
17,603 Points

The stacktrace perfectly specifies the problem. On line 15, you use a wrong operator and instead of checking if the char 'letter' is in the alphabet string, you try to assign it. You should use equal to operator instead of the assignment operator to fix your problem.