should result in the script displaying 4 since there are four words in the invocation

Write a script that lets users specify echo and wc command sequences, allowing them to use the word "pipe" to represent a pipe symbol. So input like:
echo this is a test pipe wc -w
should result in the script displaying 4 since there are four words in the invocation.

There are various ways to solve this with loops, but the easiest and fastest solution is simply to use the sed command to replace pipe with the pipe symbol. But students need to be careful that they don't get overzealous and change words like "repiped", hence the regular expression:

newcmd=$( echo $@ | sed 's/[^a-zA-Z0-9]pipe[^a-zA-Z0-9]/ | /g' )
eval $newcmd