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Java Java Objects Delivering the MVP Applying a Discount Code

is here I use for loop for string discount convert int to letter!!

how I say condition for $ sign

Order.java
public class Order {
  private String itemName;
  private int priceInCents;
  private String discountCode;

  private String normalizeDiscountCode(String discountCode){
    if(! Character.isLetter(discountCode) || discountCode == '$' ){
     throw new IllegalArgumentException (" Invalid discount code");
    }
    return discountCode.toUpperCase();
  }

  public Order(String itemName, int priceInCents) {
    this.itemName = itemName;
    this.priceInCents = priceInCents;
  }

  public void applyDiscountCode(String discountCode) {
    this.discountCode =  normalizeDiscountCode(discountCode);
  }
}

1 Answer

Hi there,

Yes, you need a for loop here. That will give you access to each character in the code so you test it to see if it is a letter or a '$'. You can't test the whole string at the same time, unfortunately!

So, start by converting the string to an array of chars. Use the .toCharArray() method with dot notation on the discountCode. You need to create a new variable to hold each character in turn, it is of type char and I called it letter for obvious reasons!

Once you've done this, you can test letter in a similar way as you've already suggested. Have a think about what you're trying to achieve. Careful with || and && as well as == and !=.

Here's the start of the loop - I'll leave you to figure out the rest but do shout if you get stuck:

for (char letter : discountCode.toCharArray()){
  // test 'letter' in here
}

Steve.