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Start your free trialDavid Zhang
946 PointsCan't use regEx here?
I'd finished this challenge using for loop.
However I want to try to use regEx to simplify the code, but it seems my regEx code was somehow wrong. I can't figure it out myself, thanks for any help.
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;
}
public int getPriceInCents() {
return priceInCents;
}
public String getDiscountCode() {
return discountCode;
}
private String normalizeDiscountCode(String code) {
if (!code.matches("/^[a-zA-Z\\$]*$/")) {
throw new IllegalArgumentException("Invalid discount code");
}
return code.toUpperCase();
}
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",
600);
// These are valid. They are letters and the $ character only
order.applyDiscountCode("abc");
order.getDiscountCode(); // ABC
order.applyDiscountCode("$ale");
order.getDiscountCode(); // $ALE
try {
// This will throw an exception because it contains numbers
order.applyDiscountCode("ABC123");
} catch (IllegalArgumentException iae) {
System.out.println(iae.getMessage()); // Prints "Invalid discount code"
}
try {
// This will throw as well, because it contains a symbol.
order.applyDiscountCode("w@w");
}catch (IllegalArgumentException iae) {
System.out.println(iae.getMessage()); // Prints "Invalid discount code"
}
}
}
1 Answer
Brendan Whiting
Front End Web Development Techdegree Graduate 84,738 PointsInteresting. It seems like the pattern that it want's shouldn't include the //
characters we normally wrap regex with. Maybe that's how regexes work in Java, I dunno.
private String normalizeDiscountCode(String code) {
if (!code.matches("^[a-zA-Z\\$]*$")) {
throw new IllegalArgumentException("Invalid discount code");
}
return code.toUpperCase();
}
David Zhang
946 PointsDavid Zhang
946 PointsI just tried whatever the patterns are(even like ^[a-z]*$), there always prompt message "Bummer: java.lang.IllegalArgumentException: Invalid discount code (Look around Order.java line 25)". I don't know what went wrong...
Brendan Whiting
Front End Web Development Techdegree Graduate 84,738 PointsBrendan Whiting
Front End Web Development Techdegree Graduate 84,738 PointsDo all those patterns include the // characters? I think that's the problem. Your original pattern worked when I removed the slashes. Basically,
code.matches
was returning false because there was a problem with the pattern, which then had us enter theif
block and threw the exception.David Zhang
946 PointsDavid Zhang
946 PointsDamn, I'd just removed the open and close / sign in my code, and it all worked no matter with or without double escape sign. I will remember this lesson.
Brendan Whiting
Front End Web Development Techdegree Graduate 84,738 PointsBrendan Whiting
Front End Web Development Techdegree Graduate 84,738 PointsSorry that's what I meant, not the escape signs.
David Zhang
946 PointsDavid Zhang
946 PointsThanks for your time and patience. I think my reading needs improving. Lmao that miscommunicating.