C Primer Plus®, Third Edition

Appendix E. The ASCII Character Set

Computers store characters by using a numeric code. The ASCII code (American Standard Code for Information Interchange) is the most commonly used code in the United States. C lets you represent most single characters directly, by including the character in single quotation marks, as in 'A' for the A character. You can also represent a single character by using the octal or hex code preceded by a backslash; for example, '\012' and '\0xa' both represent the linefeed (LF) character. Such escape sequences can also be part of a string, as in "Hello,\012my dear".

When used as a prefix in the following table, the ^ character denotes using the Ctrl key.

Decimal	Octal	Hex	Binary	Character	ASCII Name
0	0	0	00000000	^@	NUL
1	01	0x1	00000001 ...