About

ASCII is a character set originally based on the English alphabet, it encodes 128 specified characters into 7-bit binary integers (8 bits for the extended ASCII table)

ASCII means American Standard Code for Information Interchange. It was proposed by ANSI (American National Standards Institute) in 1963 and finalized in 1968.

It is the U.S. national variant of ISO/IEC 646 and is formally the U.S. standard ANSI X3.4.

It defines:

Until December 2007, ASCII was the most common character encoding on the World Wide Web, but since that time it has been surpassed by unicode character set (UTF-8,…), which includes ASCII as a subset.

On Windows, it's known as Windows-1252 (code page 1252).

Extended

The extended ASCII table is on 8byte and allows 256 characters.

Extended character List with the ALT code for the keyboard (ie Fn+Alt+code or alt+code)

Table

Because ASCII is a subset of unicode, printing the first 256 characters with unicode function will give you the Extended ASCII table.

Example with Javascript and the String.fromCodePoint function 

function character(decimal, binary, hexadecimal, character) {
  this.decimal = decimal;
  this.binary = binary;
  this.hexadecimal = hexadecimal;
  this.character = character
}
let asciiCharacters = [];
for(i=0;i<=256;i++){
    asciiCharacters.push(
        new character(
            i, 
            i.toString(2), 
            i.toString(16).toUpperCase(), 
            String.fromCodePoint(i)
            )
    );
}
console.table(asciiCharacters);

The first 32 characters are non-printable characters

Rendered by WebCode

Regular Expression Character Class

If the regular engine supports it, you can use the following regular expression class 1) to represent all ASCII characters 

[:ASCII:]

Documentation / Reference

1)
ASCII unicode set