How do I make Ctrl-A and Ctrl-X increment and decrement alphabetical characters in Vim?

Explanation

By default, Vim's <C-a> and <C-x> commands only increment and decrement numbers (decimal, hex, binary). Adding alpha to nrformats extends this behavior to single alphabetical characters, so pressing <C-a> on a gives b, on z gives a (wrapping), and on Z gives A.

How it works

• nrformats controls which value formats <C-a> and <C-x> recognize and modify
• set nrformats+=alpha appends alpha to the existing list
• Vim increments single lowercase or uppercase letters in sequence (a→b, Z→A)
• Wraps around: z → a, Z → A
• Only applies to single characters — it won't increment multi-character words
• Count prefix works: 5<C-a> on a gives f

Example

With set nrformats+=alpha, place the cursor on the character in:

step a

Press <C-a> to get:

step b

Press 5<C-a> to advance 5 letters:

step g

Tips

• Record a macro and use <C-a> to produce auto-incrementing list labels: a), b), c), ...
• Combine with a visual block g<C-a> on a column of identical letters to create a sequence: a, b, c, ...
• To check current value: :set nrformats?
• Reference: :help nrformats