How do I convert between tabs and spaces in a visual selection?

Explanation

The :retab! command converts between tabs and spaces based on your expandtab setting. When applied to a visual selection, it only affects the selected lines, allowing targeted whitespace conversion without modifying the entire file.

How it works

• :retab — replaces tabs with spaces (if expandtab is set) in leading whitespace
• :retab! — replaces ALL tabs/spaces (including within strings), not just leading whitespace
• :'<,'>retab! — applies only to the visual selection
• The conversion uses the current tabstop value

Example

:set expandtab tabstop=4
:'<,'>retab!

Before (tabs shown as →):
→   if (condition) {
→   →   return true;
→   }

After (tabs converted to 4 spaces each):
    if (condition) {
        return true;
    }

Tips

• Use :retab (without !) to only convert leading whitespace, preserving tabs in strings
• Set tabstop before retabbing: :set ts=2 | retab
• To convert spaces to tabs: :set noexpandtab | retab!
• Combine with gg=G for full re-indentation after converting