`rm(list = ls())`
`rm(list = ls(all.names = TRUE))`
`rm(list = ls(envir = .GlobalEnv))`
`gc()`
`Ctrl + L` in RStudio Console
`Session -> Restart R` in RStudio
`.rs.restartR()` in RStudio
`history(Inf)` to view history
`savehistory(“history.Rhistory”)` to save history
`loadhistory(“history.Rhistory”)` to load history
`unlink(“~/.Rhistory”)` to delete the history file
`file.remove(“~/.Rhistory”)` to remove the history file