grep in an if

2 ways to do it:
===============================
# using >/dev/null 2>&1 to prevent any output
grep "$WORKINGDIR" ~/.bak.cfg >/dev/null 2>&1
checkDir=$?

if [ $checkDir != 0 ]; then
    echo "Path doesn't exist!";
else
    echo "Path exists!";
fi
===============================
# no [ ] used here
if grep "$WORKINGDIR" ~/.bak.cfg >/dev/null 2>&1; then
    echo "Path doesn't exist!";
else
    echo "Path exists!";
fi