An ASCII character map is simply a way of keeping all the printable or screen-displayed characters in one list.
All computers store information as sets of 1’s and 0’s (bits), not as the characters we see. A group of 8 bits makes a byte, 4 bits make a nibble, and two nibbles make a byte. In this way in 8 bits we can represent numbers from 0 to 255, to each value the machine assigns a character. Let’s see some example:
- the number 32 represents a space
- from number 48 to 57 are the natural numbers from 0 to 9
- from 65 to 90 are letters from A to Z in uppercase
- 97 to 122 are lowercase letters a to z
This ordering method is used as a standard so that somehow all computers work in the same way when it comes to working with characters.
Characters do not appear the same on all computers. In order to control exactly which characters are displayed in each HTML code, it is necessary to specify it in the document header. Since there are different types of ASCII characters depending on the language.
For example, to represent the Chinese language, many more characters will be necessary than to represent English. We see an example (ascii map recommended for Europeans):<META http-equiv=”Content-Type” content=”text/html; charset=iso-8859-1″>
The need for an ASCII character map To display some special characters in HTML we can write, for example:
< & > o©
And in the browser it will appear
< & > or ©
Having a map like this can help us when we need to know which number makes which character.
How to use this mapIf you want to write a character from the ascii table you can press the ALT key + the number in DECIMAL, for example: if you press the key combination ALT+126 the character ~ will be written
ASCII code table