C Language Notes

FEATURES OF ‘C’
• Denis Ritchie developed ‘c’ language.
• Previous version was known as ‘B’ language.
• ‘C’ language is portable, mean that the program can be run on any hardware machine.
• It is modular language supports bit-wise operations and does not provide input-output statements.
• C language is modular. The large problem was divided into small sub problems.
• Because of the modularity support C language is also called as structured programming language

CHARACTER SET:
• C program basically consists of keywords, identifiers, constants, operators and some special symbols.
• The characters that can be used in ‘C’ language are Alphabets (A-Z and a-z),
• Digits (0-9), Special Characters and White Space Characters.
• Special Characters (- ~ ! @ # $ % ^ & * ( ) _ + { } [ ] : ; ’ ” < > . ? / \ |)
• White Space Characters – SPACE, TAB, RETURN, NEW LINE, FORM FEED.

KEYWORDS:
• Keywords are words whose meaning is fixed and is known by the compiler, you cannot use it for other  purpose
• I.e. we can not change the meaning of keywords.
• Keywords are also known as reserved words.
• Keywords must be in second alphabet.
THE ‘C’ LANGUAGE KEYWORDS AS PER ANSI STANDARDS.
auto double if static
break else int struct
case enum long switch
char extern near typedef
const float register union
continue far return unsigned
default for short void
do goto signed while

IDENTIFIERS:
• These are the words which are defined by programmer in a program.
• Identifiers can be the variable, symbolic constants, functions, procedures.
• The name of Identifiers should be meaningful so that the maintenance of the program becomes easy.
• The first character must be alphabet.
• Underscore (‘_’) is a valid letter.
• Reserved words i.e. keywords cannot be used as identifiers
• Identifiers names are case sensitive i.e.name and Name are treated as different Identifiers.