four areas · the command that moves code between them
Built as a memo rather than a table: the thing worth hanging it up for reads across the room, with the full reference in smaller type below it.
Three sizes in one archive — from a sheet on the fridge to a poster on the wall.
Arrows show the direction code travels forward. The commands below are ordered by how often people come back to them.
Git keeps a separate log of everywhere HEAD has been, called the reflog. Every switch, commit and reset lands in it, including work nothing else can reach any more.
So after git reset --hard the commit has not gone anywhere: git reflog shows its hash, and git switch -c brings it back on a new branch.
The defaults are ninety days for reachable entries and thirty for the rest. There is usually far less to panic about than it looks.
Why the numbers can be trusted. Every countable number here is computed from data rather than typed in, and the sheet must pass 3 independent checks before it is allowed to build — how many items there are, the order they come in, and the claim in the highlighted box itself. If one fails, there is no file.
