How to determine if a string contains a symbol?

Question

So I've been trying to figure out how I could find out if there is a symbol in the string. I've also been thinking if I should make a character array list out of the string and check each chatacter if it's a letter or the symbol '$', if its not, the IllegalArgumentException error would pop up. What do you all think?

Order.java

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;
  }

  public void applyDiscountCode(String discountCode) {
      try {
      this.discountCode = normalizeDiscountCode(discountCode);
    } catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());
    }
  }
  private String normalizeDiscountCode(String discountCode){
  if(!discountCode.contains("^[0-9]*$") || !discountCode.contains("!#%&'()*+,-./:;<=>?@[]^_`{|}~0123456789")) {
  discountCode = discountCode.toUpperCase();
  }else
      throw new IllegalArgumentException("Invalid discount code");
    return discountCode;
  }
}

Example.java

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"
    }

  }
}

Answer 1 · 2017-07-29T08:59:18Z

July 29, 2017 8:59am

I don't really understand what you're asking here. But you can use the .toCharArray() method on strings to turn the string to a char array, then use a simple for-loop looping the array to check each letter if it is '$' or a letter. Make some example code.

public class Example {
      public static void main(String[] args) {
          String text = "$ale";
          char[] letters = text.toCharArray();

                  for (char letter : letters)   {
              if (letter != '$' && !Character.isLetter(letter)) {
                  throw new IllegalArgumentException();
              }
          }
          System.out.println(text + " is valid!");
      }
}

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Edvardas Markevicius

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How to determine if a string contains a symbol?

1 Answer

Chris Tvedt

Chris Tvedt