If Condition

[Nischal Tanna]

Hi guys
I have a single query here... As we all know if an if condition has a single statement to execute we can write as below:

  
 
If <condition>
   System.out.println("OK");
else
   System.out.println("CANCEL");
 

thus we dont need any enclosing braces. However i have read somewhere that its a good practice to have enclosing brackets . thus from abve

 
If <condition>
{
   System.out.println("OK");
}
else
{
   System.out.println("CANCEL");
}
 

My question is why is it advised the latter way?...

[eric elysia]

It is easier to see what is included inside the if statement and what is not.

It makes it easier for other programmers to understand.

Look up "scope".

That's what the brackets are called, scope.

Eric

[Horatio Westock]

Firstly, the 'I' in 'If' should be lower case.

The reason for always having braces is to make absolutely clear what is included in the conditional statement. Put simply, if you always use braces, then you always have one style. If you don't, then you are using two styles: one for conditionals containing one statement, and one for multi-line ones. In my opinion, code clarity always overrules brevity.

[Nischal Tanna]

My question can be best understood this way

does during the compilation of the java file into .class files , the compiler has to explicitly insert the braces for a non braced if?...i know its not an over head if so, however we would like to keep the compiler happy

[Horatio Westock]

Don't get things the wrong way round

The compiler understands both formats, so it doesn't need to put the braces in so it can then understand them!

Don't worry about the compiler - worry about the clarity of your code.

[Stan James]

When modifying code without the braces, this is a very common error:

If <condition>
   insert something new here
   System.out.println("OK");
else
   System.out.println("CANCEL");

Actually you're fairly lucky here because the else will likely be unbalanced. But can you see how this appears to do one thing but compiles to do something else?

If <condition>
   insert something new here
   System.out.println("OK");

Now to be honest, I leave the braces out fairly often. I use the code formatter in Eclipse after every couple lines of typing so I'm not usually fooled by false indentation like that. Still, it's a pain to go back and insert braces later, and I do encourage you to get in the "always use them" habit, even if I didn't.

[David Harkness]

If you're using Eclipse (or any other modern editor), turn on templates. That way, you type "if" and hit the spacebar, and the editor puts in

if (^) {
    ...
}

where ^ is the new position of the caret for typing text and ... is just there to show you it's indented. I haven't typed a brace in Java in years. Well, okay, I have when fixing other people's code.

There is one place where I don't use braces: debugging. I have methods defined in my classes to help do Log4j logging.

protected boolean debug() { return LOG.isDebugEnabled(); }
protected void debug(String msg) { LOG.debug(msg); }
 
...
 
if ( debug() ) debug("Hi from Egypt!");

When you're learning something new, it's best to stick to one method of doing it. Once you gain experience, you'll become comfortable with altering your style as you see fit. If you try to do that early in your training, you'll hamper your progress.
[ March 07, 2005: Message edited by: David Harkness ]