This document provides an overview of the basics of the C programming language, including its character set, tokens, symbolic constants, and data types. The character set of C consists of letters, digits, whitespace, and special symbols. The smallest units of a C program are tokens, which include keywords, identifiers, constants, operators, strings, and special symbols. Symbolic constants are user-defined names for fixed values, defined using the #define preprocessor directive. C supports primary, derived, and user-defined data types, including integer, floating-point, character, and other types that specify the size and range of variable values.

1. Basics of ‘ C’
Meeta V. Prajapati
Lecturer in Computer Engineering
Computer Deparment
Government Polytechnic, Gandhinagar
Gandhinagar

2. Learning Objectives
After learning this topic you will be able to understand :
• Character Set
• C Tokens
• Symbolic Constant
• Data types

3. Character Set
• Character set is a collection of characters that can be used
to write a program of particular language.
• Every language having their own set of characters.
• Character set of c consist of letters, digits, white space and
special symbols
• Letters : A-Z , a-z
• Digits : 0-9
• White spaces : Blank space, tab, new line,form feed,
carriage return
• Special symbols : # + - * / % & ! , . : ; $ ^ | ~ () {} [] <> =
_ “ ‘ ?

4. C Tokens
• The smallest individual unit of the c program is
known as token.
• Following are the six tokens of c program :
1. Keyword
2. Identifier
3. Constant
4. Operator
5. String
6. Special Symbols

5. C Tokens
1. Keyword :
• Keywords are predefined words.
• The programmer can not change the meaning of
keyword.
• So they can not be used as a name of variable ,
constant, array , function , structure etc…
2. Identifier :
• Identifiers are user defined words.
• The meaning of identifiers is not predefined.
• User can use identifier as a name of variable, array,
function, structure, etc……

6. C Tokens
3. Constant :
• Constant means fixed value.
• The value of the constant can not change during the
execution of the program.
4. Operator :
• Operator constructs an expression along with
operands.
• Operator are used for following purpose :
1. Perform mathematical cluculation
2. Perform logical manipulation
3. Determine relationship between operands
4. Assign value of one operands or expression to another

7. C Tokens
5. String :
• A string is a sequence of characters that is enclosed
between double quotation marks.
• FOR EXAMPLE : “Hello”
6. Special Symbols :
• Following are the special Symbols used in c language :
• # ,+,-,*,/,%,&,| ,~,`,”,:,;,!,?,/,_(),{},[],<>,=,
• The C program consists of different types of tokens.

8. Symbolic Constant
• The General syntax of defining symbolic constant is given
below :
# define sysmoblic_Constant_Name value
Here,
1. #define is a preprocessor directive which is used to define
symbolic constant.
2. Symbolic_Constant_Name is a name of constant, which
user wants to define.
3. Value of the Constant represents the value , which user
can assign to the constant.
• EXAMPLE :
• # define PI 3.14

9. Data Types
• Data types is useful in programming language to instruct
compile that which kind of the value can be contained in
the variable.
• Each type of Value required different amount of memory
space. Thus data types also instruct compiler to allocate
amount of memory to hold the value of particular variable.
• Basically C data type are classified into three categories :
1. Primary Data type
2. Derived Data type
3. User Defined Data type

10. Data Types
• Integer Data Types
Data type Size in Bytes Range Value
short int 1 -128 to 127
unsigned short int 1 0 to 225
int 2 -32768 to 32767
unsigned int 2 0 to 65535
long int 4 -2147483648 to 2147483647
unsigned long int 4 0 to 4294967295

11. Data Types
• Floating Data types
Data type Size in Bytes Rang Value
Float 4 3.4 E-38 to 3.4E +38
Double 8 1.7 E-308 to1.7 E +308
Long double 10 3.4 E-4932 to 3.4 E
+4932

12. Data Types
• Character Data types
Data type Size in Bytes Range Value
Char 1 -128 to 127
Unsigned char 1 0 to 225

13. Thank you…