How do you use the Ascii Code?

Question

How would you find the ascii code for the number 253 or the letter A ?
Is there a table for it? Or is there an actual calculation process?
Please and Thank You! :))

Answer 1

ASCII is a 7-bit character code numbered from 0 to 7F in hexadecimal and from 0 to 127 in decimal. See http://aspell.net/charsets/iso646.html and http://en.wikipedia.org/wiki/ASCII .



There is no absolute logic to the assignment of characters in ASCII or in any character set, though of course the digits are normally in order and the alphabet is normally in order. You normally use a table to find any particular character.



Hexadecimal numbers are used to represent ASCII values exactly as decimal numbers are, or octal numbers, or numbers using any base. They are just numbers and can be translated from one base to another. Programmers often tend to use hexadecimal because current computers work in base 2, and base 16 (which is 2 × 2 × 2 × 2) fits into base 2 more conveniently than 2 × 5.



In the original definition of ASCII it was expected that code positions from 128 to 255 (hex 80 to FF) would often be used for extra characters. ASCII sets with such extra characters are sometimes called Extended ASCII character sets. Any character set may be also called a Code Page.



See http://www.asciitable.com/ for the extended ASCII better referred to as Code Page 437 which is the original IBM MS-DOS Code Page. This is no longer the “most popular”. A better listing is found at http://msdn.microsoft.com/en-ca/goglobal/cc305156.aspx where rarer characters are not just replaced with “_”.



Computer languages tended to have a function into which the user could plug in a decimal number and the function would return the character. This function was often called ASC() even on machines that did not use the standard ASCII set and also worked with extended ASCII characters. Such usage encouraged the improper use of the word “ASCII” for non-ASCII characters.



See the site http://www.i18nguy.com/unicode/codepages.html for a large number of code pages and articles on character sets.



The first 128 code points in Unicode contain the ASCII characters. See http://www.unicode.org/charts/PDF/U0000.pdf .

Answer 2

There is no calculation involved; it's just a "table", as you put it. You can see the complete list at the link below.



By the way, the ASCII code for a capital A is 65. A lower-case a is 97. Since ASCII is a 7-bit character encoding, it only goes up to 127; there is no 253.

Answer 3

It is also possible to directly embed an ASCII code within a string. For example the character 'K' is represented by the hexadecimal ASCII code 4B and can be embedded in a string as "\x4B". Most systems will support this type of encoding beyond the constraints of ASCII and allow full 8-bit character sets. So for example on Windows, to get a copyright sign '©' you can embed '\xA9'.

Answer 4

There is no ascii code for the number 253...

ASCII is just a way to represent alphanumeric characters and some symbols using numbers only, since the computer only stores numbers.

Answer 5

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