Problem-free once-per-line loop

The for loop has a problem with entries with spaces, whether it's file names or entries in a text file. Common solutions include changing the IFS variable to exclude spaces (so that the for loop will only use tabs and line breaks to separate entries) and piping the entries to a 'while read line; do' command. However, setting and resetting IFS each time you want to include/exclude spaces is kinda messy and the 'while read' thing means you can't make any normal use of the read command within the loop. For a once-per-line loop that doesn't present these problems, try

i=0

numberoflines=$(cat mytextfile.txt | wc -l)

while [ $i -lt $numberoflines ]; do

   let i++

   contentoflinenumberi="$(sed -n ${i}p mytextfile.txt)"

   read -p "Do you wish to see line ${i}? (y/n) " reply

   if [ "$reply" = "y" ]; then

      echo "$contentoflinenumberi"

   fi

done