Welcome to the Treehouse Community
Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.
Looking to learn something new?
Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.
Start your free trial
Atul Varma
4,285 Pointswhat's the logic ?
In the normalizeDiscountCode verify that only letters or the $ character are used. If any other character is used, throw a IllegalArgumentException with the message Invalid discount code.
public class Order {
private String itemName;
private int priceInCents;
private String discountCode;
public Order(String itemName, int priceInCents) {
this.itemName = itemName;
this.priceInCents = priceInCents;
}
public String getItemName() {
return itemName;
}
private String normalizeDiscountCode(String discountCode){
if(!discountCode.matches("[a-zA-Z]+")|| !discountCode.matches('$'){
throw new IllegalArgumentException("Invalid Discount Code");
}
discountCode = discountCode.toUpperCase();
return discountCode;
}
public int getPriceInCents() {
return priceInCents;
}
public String getDiscountCode() {
return discountCode;
}
public void applyDiscountCode(String discountCode) {
discountCode = normalizeDiscountCode(discountCode);
this.discountCode = 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",
600);
// These are valid. They are letters and the $ character only
order.applyDiscountCode("abc");
order.getDiscountCode(); // ABC
order.applyDiscountCode("$ale");
order.getDiscountCode(); // $ALE
try {
// This will throw an exception because it contains numbers
order.applyDiscountCode("ABC123");
} catch (IllegalArgumentException iae) {
System.out.println(iae.getMessage()); // Prints "Invalid discount code"
}
try {
// This will throw as well, because it contains a symbol.
order.applyDiscountCode("w@w");
}catch (IllegalArgumentException iae) {
System.out.println(iae.getMessage()); // Prints "Invalid discount code"
}
}
}
2 Answers
Thomas Nilsen
14,957 PointsTry this instead;
private String normalizeDiscountCode(String discountCode){
//Loop through the passed in String
for(char c : discountCode.toCharArray()) {
//For each letter, we check if the
//character is NOT a letter, and at the same time is not
//a dollar-sign either - we throw an exception
if(!Character.isLetter(c) && c != '$') {
throw new IllegalArgumentException("invalid discount code.");
}
}
//return the valid code
return discountCode.toUpperCase();
}
Atul Varma
4,285 PointsThank you Thomas Nilsen.