How do I enable automatic indentation?

Explanation

The autoindent option copies the indentation from the current line when starting a new line. This maintains consistent indentation while typing.

How it works

• :set autoindent copies indent from current line to new line
• Pressing o, O, or <CR> in insert mode inherits indentation
• Works independently of language-specific indentation

Example

With autoindent enabled and the cursor on an indented line:

    current indented line
    |  <- new line starts here after pressing Enter

Tips

• smartindent adds one level after { and removes after }
• cindent provides C-language-aware indentation
• filetype indent on enables filetype-specific indentation (recommended)
• indentexpr is the most flexible indentation method
• Most users want :filetype indent on rather than manual settings