delete all line in VIM

Problem

To delete all the lines of a file that is open in Vim.

Solution

1. Type gg to move the cursor to the first line of the file, if it is not already there.
2. Type dG to delete all the lines.

Deleting all the lines of a file is not a frequently used operation. So, I need a command that is easy to recall, even though it is not used much. I find dG easy to remember since I frequently use dd to delete a line, and also gg and G, which move the cursor to the first and last line of the file respectively.