Java Object equal method and Boolean value

Question

I have the following code snippet

  format(Object obj) {
    if(obj.equals("false")) {
      buffer.append("No");
    } else {
      buffer.append("Yes");
    }
  }

When debugging, I verify that the value of obj variable is a Boolean object with the value "false", but the if clause always go to the Yes instruction. Can you help me understand why?

Are you expecting something like `Boolean.valueOf(false).equals("false")` to return true? You're comparing a `Boolean` to a `String`... Maybe you want `obj.toString().equals("false")` (or `equalsIgnoreCase`). — ernest_k, Jul 21 '21 at 14:24
You're trying to compare `String` with `Boolean`. that's why you're getting `fasle` — dehasi, Jul 21 '21 at 14:24
Does this answer your question? [How to compare Boolean?](https://stackoverflow.com/questions/22491853/how-to-compare-boolean) — Nexevis, Jul 21 '21 at 14:27

Crih.exe · Accepted Answer · 2021-07-21T14:43:48.730

2

When you run obj.equals("false") you're trying to compare obj, a Boolean, with "false", which is a String.

So you can try to first convert the Boolean to a string:

if(obj.toString().equals("false")){
    buffer.append("No");
} else {
    buffer.append("Yes");
}

Or, even better, as suggested by @Nexevis, you can compare obj directly to a Boolean:

if(obj.equals(false)){
    buffer.append("No");
} else {
    buffer.append("Yes");
}

edited Jul 21 '21 at 14:43

answered Jul 21 '21 at 14:40

Crih.exe

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Wouldn't it make more sense to just do `obj.equals(false)` and compare to a `boolean` rather than use `String` as a fake boolean? – Nexevis Jul 21 '21 at 14:40
1

@Nexevis oh that's even better! – Crih.exe Jul 21 '21 at 14:44

Java Object equal method and Boolean value

1 Answers1