(K&R, §A2.5.2) The C compiler lets you use character string literals that contain 2 to 4 characters to denote a 32-bit or 64-bit integer values. Here are some examples:

Character constant	Equivalent hexadecimal integer value
'ABCDEFGH'	0x4142434445464748 (64-bit value)
'ABCDE'	0x0000000041424344 (64-bit value)
'ABCD'	0x41424344 (32-bit value)
'ABC'	0x00414243 (32-bit value)
'AB'	0x00004142 (32-bit value)

This extension cannot be turned off. There is no corresponding pragma or setting in the C/C++ Language Panel.

This feature is different from using multibyte character sets, where a single character is represented by a data type larger than 1 byte.

See "Multibyte Strings and Comments" for a discussion of a different extension relating to using character sets with more than 256 characters (such as Kanji).