1. Alphabets: C language supports all the alphabets from the English language. Lower and upper case letters together support 52 alphabets.
lower case letters - a to z
UPPER CASE LETTERS - A to Z
2.Digits: C language supports 10 digits which are used to construct numerical values in C language.
Digits - 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
3.Special Symbols: C language supports a rich set of special symbols that include symbols to perform mathematical operations, to check conditions, white spaces, backspaces, and other special symbols.
Special Symbols - ~ @ # $ % ^ & * ( ) _ - + = { } [ ] ; : ' " / ?
. > , < \ | tab newline space NULL bell backspace verticaltab etc.,
4.Space: There is no particular symbol for whitespace. It is actually a set of few characters which are:
'   ' space
'\t' horizontal tab
'\n' newline
'\v' vertical tab
'\f' form feed
'\r' carriage return.
Use isspace standard library function from ctype.We can use Actual Space or its ASCII value. both are same work in our programme

ASCII (American Standard Code for Information Interchange) is a standard character encoding used in telecommunication.
The ASCII pronounced ‘ask-ee’ , is strictly a seven bit code based on English alphabet. ASCII codes are used to represent alphanumeric data .
The code was first published as a standard in 1967. it was subsequently updated and published as ANSI X3.4-1968, then as ANSI X3.4-1977 and finally as ANSI X3.4-1986. Since it is a seven bit code , it can at the most represent 128 characters. it currently defines 95 printable characters including 26 upper case letters (A to Z) , 26 lower case letters , 10 numerals (0 to 9) and 33 special characters including mathematical symbols, punctuation marks and space character.
They represent text in, telecommunications equipment, and devices. These include numbers, upper and lowercase English letters, functions, punctuation symbols, and some other symbols. In total, there are 256 ASCII characters, and can be broadly divided into three categories: ASCII control characters (0-31 and 127) ASCII printable characters (32-126) (most commonly referred) Extended ASCII characters (128-255)