Literal Strings [Lua 5.1]

问题

So I started to learn Lua(5.1) and I saw that thing called literal strings. And I have no idea what these do. The manual says \a is a bell but when I type

print('hello\athere')

The IDE prints a weird square with 'bel' written on it. So if someone could help me and explain every one of them[Literal Strings]. that would be really helpful.

p.s. i use Sublime Text 3

回答1:

Only ASCII between 0x20 and 0x7E are printable characters. How other characters are output, including '\a' and '\b', is up to the implementation.

'\a', the ASCII 7 for BEL, is designed to be used to alert. Typical terminal would make an audible or visible alert when outputing '\a'. Your IDE choose to show a different output other than an alert. That's OK since it's up to the implementation.

回答2:

A literal is not more than a value inside the code, e.g.: 'some text'.

The '\a' is something different. A special "char", that is used to output a sound (was using the pc-speaker some aeons ago).

回答3:

Such sequences are called "escape sequences", and are found in many different languages. They are used to encode non-printable characters such as newlines in literal (hardcoded) strings.

Lua supports the following escape sequences:

• \a: Bell
• \b: Backspace
• \f: Form feed
• \n: Newline
• \r: Carriage return
• \t: Tab
• \v: Vertical tab
• \\: Backslash
• \": Double quote
• \': Single quote
• \nnn: Octal value (nnn is 3 octal digits)
• \xNN: Hex value (Lua5.2/LuaJIT, NN is two hex digits)

来源：https://stackoverflow.com/questions/26803512/literal-strings-lua-5-1