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Start your free trialAndre Kucharzyk
4,479 PointsWhat's wrong with my code #2
After I submit code, I get error like this:
java.lang.IllegalArgumentException: Invalid discount code at Order.normalizeDiscountCode(Order.java:11) at Order.applyDiscountCode(Order.java:38) at JavaTester.run(JavaTester.java:89) at JavaTester.main(JavaTester.java:43)
public class Order {
private String itemName;
private int priceInCents;
private String discountCode;
private String normalizeDiscountCode(String discountCode) {
boolean isDollar = false;
for(char letter : discountCode.toCharArray()){
if(!discountCode.matches("[a-zA-Z]") && !(letter == '$')){
throw new IllegalArgumentException("Invalid discount code");
}
}
return discountCode.toUpperCase();
}
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);
}
}
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(); // $ALE
try {
// This will throw an exception because it contains numbers
order.applyDiscountCode("ABC123");
} catch (IllegalArgumentException iae) {
System.out.println(iae.getMessage()); // Prints "Invalid discount code"
}
try {
// This will throw as well, because it contains a symbol.
order.applyDiscountCode("w@w");
}catch (IllegalArgumentException iae) {
System.out.println(iae.getMessage()); // Prints "Invalid discount code"
}
}
}
1 Answer
Simon Coates
28,694 PointsI don't know if your regular expression is correct. However, testing the complete string for every character is monumentally repetitive. A standard solution uses the Character class's static isLetter method.
private String normalizeDiscountCode(String discountCode) {
//boolean isDollar = false;
for(char letter : discountCode.toCharArray()){
if(!Character.isLetter(letter) && letter != '$'){
throw new IllegalArgumentException("Invalid discount code");
}
}
return discountCode.toUpperCase();
}
I don't know what i'm doing with regex/pattern matching, but it I took a guess. Maybe something like:
private String normalizeDiscountCode(String discountCode) {
if(!discountCode.matches("[a-zA-Z$]*")){
throw new IllegalArgumentException("Invalid discount code");
}
return discountCode.toUpperCase();
}
Andre Kucharzyk
4,479 PointsAndre Kucharzyk
4,479 PointsWell, I have already used the first option with isLetter to pass through the exercise, but I still don't know what I did wrong with defining regex the way I did.
Simon Coates
28,694 PointsSimon Coates
28,694 PointsI think the matches method is trying to work out if the complete string matches the pattern. My regex [a-zA-Z$]* means that i'm testing for zero or more instances of the characters in the []. If that describes the complete string, i get a match.
Simon Coates
28,694 PointsSimon Coates
28,694 Pointsyour regex works if you are only operating on the character, rather than the complete discount code. eg.
However, this is equivalent to the Character.isLetter approach.