||What is a character code?
||Numbers that represent
When handling characters
on a PC, it is normal to replace them with
numbers called character codes.
Character codes are no more than numbers, so if
the same number is given to different characters,
it becomes impossible to judge which character it
is expressing. For this reason, it is necessary
to set down strict rules on which number should
be given to which character.
Normally, official organizations such as JIS
collect a certain range of characters into a
group, called a character set, to which
non-duplicate numbers are then given.
However, when creating a character set, one
character code is given to a group of characters
that, within limits, differ only slightly.
This takes real-world usage into account. Some
Kanji, although they are the same character, have
two or more ways of being written. For example,
there are some people who consider slight
variations in shape, the number of strokes, the
existence of a small curve at the end of a
stroke, and so on, to be important, and refuse to
recognize their name without such features.
However, JIS considers them to be the same
character and gives these characters only one
character code. Recognizing people's claims
without limit would result in the number of
characters increasing explosively, increasing the
cost of systems. This would reduce the merits of
PCs as products that can be used economically.
Thus, when creating a character set, rules are
laid down and characters that have a certain
level of difference are given separate character
codes based on those rules.
Integrating slightly different characters into
one in this way is called