Hi,

Just a simple question, with a nice opportunity to clean my code :)

I'm not sure when I need to use brackets in a for loop, depending on the code that needs to be executed for each iteration.

Example, I have:

for(mat=0;mat<mNrMaterials;++mat) 
{	
	if(materials[mat]) ++mEffect[fx].nrMaterials; 
}

Would the result be the same if I use:

for(mat=0;mat<mNrMaterials;++mat) 
	if(materials[mat]) ++mEffect[fx].nrMaterials; 

I know that I can leave the brackets out if I just have one line of code for each iteration, like:

for(int i=0;i<5;++i)
  something[i] = i*2;

Anyone?

Thank for the reply/ info.

Always a difficult balance between compact and clean code, good to know that functionally both works.

Clean your code by always using braces even if they are not required by the syntax.

Consistent code is clean code.
Omitting braces “just because you can” is inconsistent. It is a sign you seek to put forth the minimal effort allowed by the syntax rather than to just keep things the same everywhere.
It unnecessarily puts you or those maintaining your code later at risk of hard-to-spot bugs.

int iSum = 0;
for ( int i = 0; i < 20; ++i )
    iSum += i;

“It works. Humm, but I want to see what the value of iSum is on each iteration.”

int iSum = 0;
for ( int i = 0; i < 20; ++i )
    cout << iSum << endl;
    iSum += i;

“What it always prints 0 and my algorithm broke too, WTF!?”

There is just no need for this kind of risk.
As mentioned already, clearer code is more important than compact code.

Omitting braces for the sake of syntactical exceptions just doesn’t make sense.


L. Spiro

The typical example used to illustrate the difficulty of not using braces is this:

if( foo )
    if( bar )
        actionA();
else
    actionB();

The indentation hints that the else is paired with the "foo" conditional, but the parser will ignore this and pairs it with "bar". Almost all professional style guides I've seen require braces for loops and conditionals.

I use unbraced forks only for if-wrapped return, continue, break, and throw statements, because those don't have "else" forks; any subsequent code is an "else" after that.

But, I also tend to write very dense loops, frequently without an actual body, so sometimes the body of my loops ends up being a single semicolon, ie

for(int i=0, j=arraylength-1; i<j; array[j--]=array[i++]) ;

And that just becomes more unreadable when I waste essentially blank lines putting empty braces on the following couple lines.