_
Underscore
- Unicode
- U+005F
- Category
- Punctuation
- HTML Entity
- _
- CSS
- \005F
The underscore (_), Unicode name "low line", is a horizontal line drawn on the baseline. It began on typewriters, where typists backspaced over a word and struck it to underline it; on screens it lives on as a character in its own right. Today you meet it in usernames, email addresses, file names and programming identifiers — anywhere a space is not allowed but the words still need to be kept apart (first_name, my_photo.jpg).
On a US keyboard the underscore is Shift and the key right of 0 (the hyphen key). On an iPhone it is on the #+= page; on Android, on the ?123 or =\< page. In chat apps such as WhatsApp and Telegram, a word wrapped in underscores (_like this_) is rendered in italics.
On a US keyboard the underscore is Shift and the key right of 0 (the hyphen key). On an iPhone it is on the #+= page; on Android, on the ?123 or =\< page. In chat apps such as WhatsApp and Telegram, a word wrapped in underscores (_like this_) is rendered in italics.
How to Type
- Windows
- Shift+- · Alt+95
- macOS
- Shift+-
- Linux
- Shift+- · Ctrl+Shift+U 5f
- HTML
- _
In Programming
The underscore is the one punctuation mark allowed in identifiers in almost every language: snake_case names in Python, Ruby and SQL, CONSTANT_CASE constants, a leading _ for private members by convention, and __dunder__ methods in Python. A lone _ is the throwaway variable in Python, Go and Rust. In SQL LIKE patterns _ matches exactly one character; in regex it is part of \w; in Markdown _text_ is italic.
Tags
underscore
low line
underline symbol
snake case
shift hyphen
alt 95
username symbol
keyboard symbol
ascii
programming