Answer:

Here is the example fragment properly indented. Matching ifs and elses have matching colors.

if ( a == b )
  
  if ( d == e )
    total = 0;
  
  else
    total = total + a;

else
  total = total + b;

Make Matches clear with Braces

Sometimes you must use braces { and } to say what you want. An else inside of a pair of braces must match an if also inside that pair. Sometimes you don't need braces, but use them to make clear (to human readers) what you intend. Here is the complete rule for matching ifs and elses:

Rule for Matching if and else: Within each pair of matching braces: start with the first if and work downward. Each else matches the closest previous unmatched if. An if matches only one else and an else matches only one if.

Here is a program fragment that uses braces. The blue if matches the blue else. The braces are needed to make this so.

if (  ch == 'q' )
{
    if ( sum == 12 )
        ch = 'b' ;
}
else
    ch = 'x' ;

QUESTION 13:

Match the ifs and elses in the following:

if ( a == b )
{  
if ( d == e )
  total = 0;
  
else
  total = total + a;
}