Comments are needed for Rule 6-4-2? and should be placed inside the "else" block?

[chenzhuowansui]

Hi,

With regards to Rule 6-4-2

All if … else if constructs shall be terminated with an
else clause.

we have some different interpretations, so could you kindly help clarify the following questions for us:
1. The rule only talks about "if … else if constructs shall be terminated with an else clause." in the title, and doesn't mention anything about adding necessary comments for the else clause in the title. However, in the rationale part, it indeed mentions that the final else statement should "either take appropriate action or contain a suitable comment", the question is: shall we take the rationale part into account to interpret this rule, more specifically, is the following code snippet compliant?

Code:

if ( x < 0 )
{
log_error ( 3 );
x = 0;
}
else if ( y < 0 )
{
x = 3;
}
else
{
}

2. If the comments are necessary, where shall it be placed: right in the else block? or any places around the else clause, for example, are the following cases compliant?

Code:

if ( x < 0 )
{
log_error ( 3 );
x = 0;
}
else if ( y < 0 )
{
x = 3;
}
// No change in value of x
else
{
}

Code:

if ( x < 0 )
{
log_error ( 3 );
x = 0;
}
else if ( y < 0 )
{
x = 3;
}
else // No change in value of x
{
}

Code:

if ( x < 0 )
{
log_error ( 3 );
x = 0;
}
else if ( y < 0 )
{
x = 3;
}
else
// No change in value of x
{
}

Many thanks in advance!