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Start your free trialmelissa zhang
760 PointsIn the normalizeDiscountCode verify that only letters or the $ character are used. If any other character is used, throw
Hi, I can't figure out how to code this question. Can anyone help and show me the answer? many thanks.
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 discountCode){
String symbol = "$";
if(discountCode.isLetter(discountCode) ||discountCode !=symbol){
throw new IllegalArgumentException("Invalid discount code");
}
return discountCode.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
gyorgyandorka
13,811 PointsHi Melissa! You have to iterate through the discountCode
string, and to be able to do that, you should first convert it to a char array, using the String class's toCharArray()
method. Now you should use a for loop and do the check for every character. Be aware that the isLetter
method is not defined in the String
class, but it's a static method in the Character
class, and accepts a char
type argument (so you should call it on the class directly, like Character.isLetter(myCharacter)
).
Also note: the first part of the condition check should actually check for falseyness (should be inverted with a !
), since we're throwing the exception if our character is not a letter (or $ sign). Because of this, instead of ||
we should use &&
, since we're checking if neither is true.
melissa zhang
760 Pointsmelissa zhang
760 PointsThank you very much.
gyorgyandorka
13,811 Pointsgyorgyandorka
13,811 PointsHello, Sarantis! First of all: you can edit your post/comment and format your code with syntax highlighting like me and Melissa, check the "Markdown Cheatsheet" link below the textbox.
Almost every hint is there in the answer I've given to Melissa:
discountCode
string, not the string itself, so you should iterate it through (it should be converted to achar[]
first with the.toCharArray()
method of theString
class); in fact, theisLetter()
method accepts a character, it doesn't work for a string argumentisLetter()
is a static method of theCharacter
class, so you shouldn't call it on the character in question, but on theCharacter
class itself (and give it your character as argument)try to finish it yourself first, but...
SPOILER
here is the solution (for reference):