The character are a raw material contain information.It is pre define set which help in daily life and computer language too like help to build programs etc.
It contain the set like Alphabets ,Digits,Special characters,white space.
Alphabets contain the Alphabets in uppercase from A to Z and in lowercase a to z
Digits contain 0,1,2,3,4,5,6,7,8,9
Special characters contain !,@,#,$,%,^,&,*,(,),{,},[,],_,-,+,=,?,/,<,> etc
white space characters contain \t,\n,\v,\a,\',\0,",\? etc
C/C++ contain 180 reserved words,If once any word saved in library then it always be a reserved word after this we well not change or you can say that its pree defined in programing language this one the few important reserved words are t
Break Int d case long d chard register d continue default double d do else entry extren d flaot d for goto return switch struct short d sizeof while do while union etc
In user defined word like the pre defined word can be change like any reserved word can be change but the meaning of the word remain same.The keyword use for to defined user word is typedef ,the method is like
typedef knowndatatype newname;
like we try to change any word here
typedef Int class;
here the int is pree defined but know we can use here class instead of int
variable is a name for space in computer member where the information can be store in the shape data.The variables can me small in size or bi it depend on the needs.
variable naming can be use to identifies the variable to store the data,each and all variables must start with the letter and rest of name contain ,number,underscore character etc
variable type There are few type of variable like
bool store the value even true or false
char this is the type of integer but store only one octet means one bit
int represent integer use all natural size of integer for computer
float single-precision floating point value
double double-precision floating point value
void use for to show the absence of type
wchar-t use for a wide char character type
Constants
Numeric constant are
integer constant It contain the number without any fraction or exponent.there are three type of integer numeric constant like decimal digital start from 0 to 9,octal digits start from 0 to 7 hexadecimal are 0 1 2 3 4 5 6 7 8 9 A B C D E F
Floating constant It contain the number either fractional or no fractional or exponent form like E-5 represent 10-5 thus -0.22E-5 = -0.0000022.
Exponential real constant it contain speciel numbers and not allow any digit after decimal and denoted with E.
Non Numeric constant(character constant)
Single Character constant it contain the single quotation around any charahter like 'a', 'B' etc
String constant It contain double quotation string like "done", "x" etc
the picture of constant are
