Boolean not applying correctly

Question

Alrighty, so I have a program that is supposed to take the first name of the customer, and regardless if the letters in the name are capitalized or lower case, if they are Mike or Diane, it sets the discount to being true and then later on applies the discount. By default discount = false.

Heres getting the name and setting discount to true:

if (firstName == "Mike" || firstName == "Diane")
  {
     discount = true;
  }

And here's later on when I'm trying to apply the discount and lower the cost:

if (discount == true)
  {
     System.out.println("You are eligible for a $2.00 discount!");
     cost = cost - (2.00);
  }

However the problem is that when I use Mike or Diane, whether capitalizing or not, it simply does not apply the discount to the price. It compiles and runs, it just doesn't apply the discount.

Use `String`'s `equals` method to compare string values, not the `==` operator. — rgettman, Feb 03 '14 at 18:47
1) take a look at [how-do-i-compare-strings-in-java](http://stackoverflow.com/questions/513832/how-do-i-compare-strings-in-java). 2) don't use `if (discount==true)`. Just write it as `if(discount)`. This way you will never make mistakes like `if (discount = true)`. — Pshemo, Feb 03 '14 at 18:47

But I'm Not A Wrapper Class · Answer 1 · 2014-02-03T18:53:35.630

3

Use .equals(...) to compare String values:

"Mike".equals(firstName)

== compares the references of Java Objects. It's perfectly fine to use == to compare primitive data types values (ex. boolean, int, double, etc.).

If you want to ignore the case of the characters, then use .equalsIgnoreCase(...):

"Mike".equalsIgnoreCase(firstName)

Check out the String API, it has a lot of useful methods.

edited Feb 03 '14 at 18:53

answered Feb 03 '14 at 18:48

But I'm Not A Wrapper Class

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This is not case insensitive. – admdrew Feb 03 '14 at 18:52

score 2 · Answer 2 · answered Feb 03 '14 at 18:49

2

You should not use == (reference equality) for determining String equality, luckily there is an String#equalsIgnoreCase(String) method.

boolean discount = ("Mike".equalsIgnoreCase(firstName) || 
    "Diane".equalsIgnoreCase(firstName));

answered Feb 03 '14 at 18:49

Elliott Frisch

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Happy · Answer 3 · 2014-02-03T18:54:44.260

1

== compares the reference of the strings. You can use equals:

Solution:

if(firstName.equalsIgnoreCase("Mike") || firstName.equalsIgnoreCase("Diane"))
{
    discount = true;
}

Tip:

Nevertheless, it is better to write "Mike".equalsIgnoreCase(firstName) instead of firstName.equalsIgnoreCase("Mike"), because you are sure that Mike is not null. firstName.equalsIgnoreCase("Mike") can throw a NullPointerException if firstName is null.

edited Feb 03 '14 at 18:54

answered Feb 03 '14 at 18:49

Happy

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1

Does not ignore case. – Elliott Frisch Feb 03 '14 at 18:52
Yes he should use the method you gave in your answer. I edit my post, thank you. – Happy Feb 03 '14 at 18:54

score 1 · Answer 4 · answered Feb 03 '14 at 18:49

1

you can use equalIgnoreCase Method

"Mike".equalsIgnoreCase(firstName)

like

if(firstName.equalsIgnoreCase("Mike") || firstName.equalsIgnoreCase("Diane"))
    {
        discount = true;
    }

answered Feb 03 '14 at 18:49

Girish

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Boolean not applying correctly

4 Answers4