deno repl starts an read-eval-print-loop, which lets you interactively build up program state in the global context.

Keyboard shortcuts

Keystroke Action
Ctrl-A, Home Move cursor to the beginning of line
Ctrl-B, Left Move cursor one character left
Ctrl-C Interrupt and cancel the current edit
Ctrl-D If if line is empty, signal end of line
Ctrl-D, Del If line is not empty, delete character under cursor
Ctrl-E, End Move cursor to end of line
Ctrl-F, Right Move cursor one character right
Ctrl-H, Backspace Delete character before cursor
Ctrl-I, Tab Next completion
Ctrl-J, Ctrl-M, Enter Finish the line entry
Ctrl-K Delete from cursor to end of line
Ctrl-L Clear screen
Ctrl-N, Down Next match from history
Ctrl-P, Up Previous match from history
Ctrl-R Reverse Search history (Ctrl-S forward, Ctrl-G cancel)
Ctrl-T Transpose previous character with current character
Ctrl-U Delete from start of line to cursor
Ctrl-V Insert any special character without performing its associated action
Ctrl-W Delete word leading up to cursor (using white space as a word boundary)
Ctrl-X Ctrl-U Undo
Ctrl-Y Paste from Yank buffer
Ctrl-Y Paste from Yank buffer (Meta-Y to paste next yank instead)
Ctrl-Z Suspend (Unix only)
Ctrl-_ Undo
Meta-0, 1, …, - Specify the digit to the argument. starts a negative argument.
Meta-< Move to first entry in history
Meta-> Move to last entry in history
Meta-B, Alt-Left Move cursor to previous word
Meta-Backspace Kill from the start of the current word, or, if between words, to the start of the previous word
Meta-C Capitalize the current word
Meta-D Delete forwards one word
Meta-F, Alt-Right Move cursor to next word
Meta-L Lower-case the next word
Meta-T Transpose words
Meta-U Upper-case the next word
Meta-Y See Ctrl-Y

Special variables

Identifier Description
_ Yields the last evaluated expression
_error Yields the last thrown error