Today we will discuss different element of C language user in programming .I hope you understand the
first chapter quite well.
=>C character sets
1.The character that are used in C programs are given below.
♦Alphabet -: A,B,C…….Z(Upper case)
a,b,c……….z(lower case)
♦Digits -:0,1,2,3…….9
♦Special characters and symbols-: +,-,/,,<,>,),(,{,} etc.
Very ImpNote:In ‘C’ language everything is written in lower case letter because ‘C’ is case sensitive language..
=>C Tokens
Individual words and punctuation marks are called tokens
Similarly in a ‘C’ program one smallest individual unit are known as tokens.
C has various types of tokens.
1.Keywords:-
keywords are those words which has been already explained to the ‘C’ compiler/The keywords can’t be used as identifier because if we do so we are tring to assing a new meaning to the word which is now allowed by the compiler. Keywords are also called reserve words.All keywords must be written in lowercase letters. Some eg are int,else,double,goto,shot,do,while,union,if,char,float etc.
2. Identifiers-:
All the words that we will use in our C programs will be either keyword or identifiers.Keyword are predefined and cannot be changed by the user while identifiers are user defined words and are used to give names like variables ,functions,structure etc.
3.Constants:-
as according to the name constants is a values that cant be changes during the execution of the programs C supports various types of constants as following. numeric constant,character constants . they are then divide in to two parts.
1.Numeric constants
a.integer constants(range of int is from -32768 to +32767)
b.real constants(fractional form,exponential form)
2.Character constants
a.Single character ( e.g ‘a’,b’,’g’,’=’,’@’ etc)
b.string constants (e.g “abd”,”a”,”my name”,”gammerson” etc)
3.Variables:-
Variables is a name that can be used to store values.variables can be take different values but one at a time .those values can be changes during execution of the program.data type is associated with each variable.Data type of the variable decides what type of value can be store in the variable.
Chapter 3—->
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