count the empty lines in a file

grep "^$" filename.txt

No of empty lines in a file
grep "^$" filen| wc -l
or
grep -c "^$" a.sh

or AWK

awk '{
if (NF == 0)
{
# print "Here comes the empty line"
print $0
}

-----------------------
file displaying without its empty lines

awk '{
if (NF != 0)
{
# print "Here comes the empty line"
print $0
}
}' a.sh

}' a.sh | wc -l


HERE
NF=number of fields in the current line
$0=current line