I can never remember how to do heredocs

heredoc.sh

#!/usr/bin/env bash

# heredoc with shell expansion
cat << EOF
The current working directory is: $PWD
You are logged in as: $(whoami)
EOF

# heredoc with shell expansion into a variable
myvar=$(cat << EOF
The current working directory is: $PWD
You are logged in as: $(whoami)
EOF
)
echo "${myvar}"

# heredoc without shell expansion (the delimiter has quotes)
cat <<- "EOF"
The current working directory is: $PWD
You are logged in as: $(whoami)
EOF

# heredoc without shell expansion (the delimiter has quotes)
myvar2=$(cat <<- "EOF"
The current working directory is: $PWD
You are logged in as: $(whoami)
EOF
)
echo "${myvar2}"