| ||Alert (bell)|
In a program,
where data might come from a disk file or other source,
you might need to match characters other than the usual ones.
For example, to match a "bell" character, use
To match a tab character, use
The table shows some others.
These cannot be tested in the applet on the previous page
because the applet does not let you enter these characters.
Users might enter control characters from the keyboard
by holding down the "control" key and striking another key.
\cG matches control-G.
This is the same character as "Alert" and corresponds to
the same character specified as 0x07 in hexadecimal.
For much more about control characters, see the Wikipedia article here: Control Character.
Do all characters correspond to an octal (or a hexadecimal) code that describes a bit pattern?