One line if statements

Question

I was recently involved in an argument with a coworker involving one line if statements and wanted to see what stackoverflow thought.

Do you feel that the statement should be written as:

if(condition)
{
     statement = new assignment;
}

OR

if(condition)
    statement=new assignment;

please provide a good reason for your decision.

Answer 1

if you should really use one line if

 if(condition) statement=new assignment;

will be better since its one line, it should contain one operation.

Answer 2

I've always been a fan of braces. If someone were to modify a oneline if statement like so:

if(condition) statement=new assignment;

to

if(condition)
statement = new assignment;
another statement;

You won't get the expected behavior.

Using the braces pretty much insures that if someone modifies an if statement, they'll make sure to put the right statements in the right place.

Answer 3

I always do one-line if statements sans-brackets. The presence of brackets indicates (syntactically correctly) that "oh, I can do something else in here..." and I don't like the temptation. Anything that involves more than one statement should be broken up into multiple lines with proper brackets.

Answer 4

I always use enclosing braces to reduce the risk that someone (including myself) will later introduce a bug by editing the code around the if statement without paying careful attention to which line(s) belong as part of the if-condition.

EDIT:

Here's a live example if this I just happened to come across in some old code:

if (form.validateUpload (messages, this))
    return getErrorOutcome (ctx, messages);
    if (LOG.isInfoEnabled ())
        LOG.info ("CREATING UPLOAD");

Notice how both "if" statements are in the main block of code but due to poor formatting, at first glance they appear to be nested. Sure any "good" programmer should quickly see what's happening, but why cause any unnecessary confusion?

Answer 5

I would go without the brackets.

The only reason you would need the brackets is if you had multiple statements inside the block.

Sounds like a waste of an argument though.

Answer 6

if(condition)
    statement=new assignment;

or

if(condition) statement=new assignment;

Answer 7

As a rule, I abhor one-line ifs except in this Perl case

operation if condition;

Answer 8

This really depends on the coding style of your group. The group should have consistent coding standards. For my current group we always use:

if (condition) {
  statement = new assignment;
}

We do this to prevent mistakes caused by forgetting the braces after the if statement, such as:

if (condition)
   statement1;
   statement2; 
//statement2 is not part of the if statement, but it looks like it because of wrong indentation

Another group that I worked with until just recently always used this syntax for one-line if statements:

if (condition)
    statement1;

Personally I don't like this as much because it's less explicit; but the most important thing is to stick to a consistent coding standard for your group or project, so that code you write looks like code your co-workers write, and is just as easy to read for everyone in the group.

The conventions of your IDE or environment can provide a good basis for your coding standards, and may even be tailored to your group's style.

Answer 9

I have auto-format setup to kill your one-liner, which puts it on two lines. As such, it needs braces.

Answer 10

if (condition)
{
    statement = new assignment;
}

is what I would write. Namely because I like tidy code which saves time to read/edit/understand.

In very few cases I'd make an exception normally only when I'm quick and dirty coding something for debugging etc.

A one line if statement is always very easily corrupted by how the semicolon is placed.

Answer 11

I always use enclosing brackets and I never code one line ifs, my approach looks like this

if(condition) { 
    statement = new assignment; 
}

because I code Java and that's the convention for the language. Check:

http://java.sun.com/docs/codeconv/html/CodeConventions.doc6.html#449

Note: if statements always use braces {}. Avoid the following error-prone form:

if (condition) //AVOID! THIS OMITS THE BRACES {}!
    statement;

The use of brackets prevent bugs: some else could add later new sentences that are suposed to be executed if the condition and forgetting the brackets