Case Changing

~ flips one character. gU/gu/g~ are operators.

Keys: ~, gU, gu, g~

~ toggles the case of the character under the cursor. gU is an uppercase operator; gu is lowercase; g~ toggles. Each takes a motion: gUiw uppercases the inner word.

Three operators for case: gU uppercases, gu lowercases, g~ toggles. Each takes a motion, just like d and y. ~ alone is a one-shot toggle of the character under the cursor.

Toggle case of cursor character

Key	Note
`~`

Uppercase inner word

Key	Note
`g`
`U`
`i`
`w`

Lowercase inner word

Key	Note
`g`
`u`
`i`
`w`

Toggle inner word

Key	Note
`g`
`~`
`i`
`w`

Uppercase whole line

Key	Note
`g`
`U`
`U`

~ — toggle case

gU — uppercase operator

gu — lowercase operator

g~ — toggle case operator

Doubled forms (gUU, guu, g~~)

Worked example — gUw and ~

Change case without retyping.

Step 2 · `gUw` · gUw — uppercase one word.

Step 3 · `0~` · ~ — toggle one char's case.

▶ Try this in the simulator

See also: The Universal Grammar, The Vim Grammar