What are the advantages and disadvantages between these coding styles?

Question

Some people use the following style

setting
{
     a=1
    ,b=2
    ,c=3    
}

and the other ones use the style below

setting
{
    a=1,
    b=2,
    c=3 
}

I use the latter style but I wonder why some people prefer the former style? Is there anything I missed?

Answer 1

In ConTeXt, the two are not equivalent. The former sets a to be 1\n etc. This leads to a very common beginner error:

\setupsomething
    [...]
    [ key1=value,
      key2=value,
      key3=value
    ]

Notice that the last line does not contain a comma, so key3 is set to be equal value\n. To avoid that use

\setupsomething
    [...]
    [ key1=value,
      key2=value,
      key3=value,
    ]

or

\setupsomething
    [...]
    [ key1=value,
      key2=value,
      key3=value]

Answer 2

Usually when setting keys you can do it this way:

{
    a=1,
    b=2,
    c=3,
}

Then all rows can be commented out and additional rows can be inserted anywhere.