Is it ok if I omit curly braces in Java? [closed]

Question

I've searched for this, but couldn't find an answer and for whatever reason I was too ashamed to ask professor, due to that feeling when hundreds of people stare at you...

Anyhow, my question is what's the importance of having brackets? Is it OK if I omit them? Example:

for (int i = 0; i < size; i++)  {
   a += b;
}

vs

for (int i = 0; i < size; i++)
   a += b;

I know both of them will work, but if I omit the brackets (which I tend to do a lot, due to visibility) will that change anything, anything at all? As I said, I know it works, I tested it dozen of times, but now some of my uni assignments are getting larger, and for some reason I have irrational fear that in the long run, this my cause some problems? Is there a reason to fear that?

Answer 1

I think that loosing curly braces is good, if you are also using auto-format, because than your indentation is always correct, so it will be easy to spot any errors that way.

Saying that leaving the curly braces out is bad, weird or unreadable is just wrong, as whole language is based on that idea, and it's pretty popular (python).

But I have to say that without using a formatter it can be dangerous.

Answer 2

using redundant braces to claim that code is more maintainable raises the following question: if the guys writing, wondering about and further maintaining the code have issues like the ones described before (indentation related or readability related) perhaps they should not program at all...

Answer 3

Using braces makes the code more maintainable and understandable. So you should consider them by default.

I sometimes skip using braces on guard clauses to make the code more compact. My requirement for this is that they're if statements that are followed by a jump statement, like return or throw. Also, I keep them in the same line to draw attention to the idiom, e.g:.

if (!isActive()) return;

They also apply to code inside loops:

for (...) {
  if (shouldSkip()) continue;
  ...
}

And to other jump-conditions from methods that are not necessarily at the top of the method body.

Some languages (like Perl or Ruby) have a kind of conditional statement, where braces don't apply:

return if (!isActive());
// or, more interestingly
return unless (isActive());

I consider it to be equivalent to what I just described, but explicitly supported by the language.

Answer 4

If you use brackets your code is more readable. And if you need to add some operator in same block you can avoid possible errors

Answer 5

For most cases, the answers mentioned so far are correct. But there are some disadvantages to it from the security perspective of things. Having worked in a payments team, security is a much stronger factor that motives such decisions. Lets say you have the following code:

if( "Prod".equals(stage) )
  callBankFunction ( creditCardInput )
else
  callMockBankFunction ( creditCardInput )

Now lets say you have this code is not working due to some internal problem. You want to check the input. So you make the following change:

if( "Prod".equals(stage) )
  callBankFunction ( creditCardInput )
else
  callMockBankFunction ( creditCardInput )
  Logger.log( creditCardInput )

Say you fix the problem and deploy this code (and maybe the reviewer & you think this won't cause a problem since its not inside the 'Prod' condition). Magically, your production logs now print customer credit card information that is visible to all the personnel who can see the logs. God forbid if any of them (with malicious intent) gets hold of this data.

Thus not giving a brace and a little careless coding can often lead to breach of secure information. It is also classified as a vulnerability in JAVA by CERT - Software Engineering Institure, CMU.

Answer 6

If you have only one statement inside the loop it is same.

For example see the following code:

for(int i=0;i<4;i++)
            System.out.println("shiva");

we have only one statement in above code. so no issue

for(int i=0;i<4;i++)
            System.out.println("shiva");
            System.out.println("End");

Here we are having two statements but only first statement comes into inside the loop but not the second statement.

If you have multiple statements under single loop you must use braces.