C++ Key Words or Reserved Words
Definition:
The
words we directly implemented and cannot change during writing a program called
key/reserved words of C++
Eg.
Double, main, if and else etc.
Explanation:
About
reserved words and keywords the some author says both are different but most of
author says these are slide difference. I always agree both are same because we
can’t change our self if we change these word then this method would be against
of C++ programming rule.
The
reserved words of C++ may be conveniently placed into several groups. In the
first group we put those that were also present in the C programming language
and have been carried over into C++. There are 32 of these, and here they are:
auto const
double float int
short struct unsigned
break continue
else for long
signed switch void
case default
enum goto register
sizeof typedef volatile
char do
extern if return
static union while
There
are another 30 reserved words that were not in C, are therefore new to C++, and
here they are:
asm dynamic_cast namespace
reinterpret_cast try
bool explicit new
static_cast typeid
catch false operator
template typename
class friend private this using
const_cast inline
public throw virtual
delete mutable protected true wchar_t
The
following 11 C++ reserved words are not essential when the standard ASCII
character set is being used, but they have been added to provide more readable
alternatives for some of the C++ operators, and also to facilitate programming
with character sets that lack characters needed by C++.
and bitand
compl not_eq or_eq
xor_eq
and_eq bitor
not or xor
Note
that your particular compiler may not be completely up-to-date, which means
that some (and possibly many) of the reserved words in the preceding two groups
may not yet be implemented.
Variables:
Definition:
Those words or letter we write in our program is known as
variables.
Eg. Sum, x, I, salary and num1.
Explanation:
If you starts your variable with number or digit then compiler
generate error (1num, 444x,5n)
But you should always start your variable with alphabets. Always
use variable creative if you use “n1”,
In small Program you understand the “n1” but in large Program you are unable to understand or other Programmer can’t understand your program properly.Data Types:
Those types of Data programmers wants to store in memory is known
as data types.
Eg. Int, float, double, short and long etc.
Data types and memory:
Complete data types we written as: int
sum. The reason of the highlighted
data is this sum is variable and which is reference of memory and lies of data
which gives reference sum in memory is integer. For example int sum=10. Then the 10 is reference as in computer memory.
Memory
10
|
||||
Sum
Basic input and output of C++:
Definition:
During running the program if user gives some information to
computer called input and it’s vice versa is known as output.
Explanation:
Cout
is key word and we use for giving output for user. Cin is also keyword we use for taking input
from user. We should always use << sign for output
and >> sign
for input.
Some important basics for writing program:
\t =>
to giving space between text \b=> to giving backspace between text
\n=> to start text for new line endl =>
to end line
Eg. For Basic input and output of
C++
watch My Complete Video Lecture About first post & this topic:
#include<iostream>
Using namespace std;
Int main ( )
{
Int sum;
Int num1,
num2;
Cout
<< ”\t please enter the first
Number ” << endl ; //for out put
Cin>>num1;
//for input
Cout
<< ”\t please enter the first
Number “ << endl ; //for out put
Cin>>num2; //for input
Sum = num1
+ num2;
Cout
<< ”\t The sum of given Numbers
is: ” << sum<< endl ; //for
out put
Cout<<”\n\n\n\n\n”;
System (“Pause”);
}
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