C++ में Constants क्या है? उसके प्रकारों की संपूर्ण जानकारी

#include<iostream> 
using namespace std;
int main() 
 {
    const int myNum = 45;
    const float PI = 3.14;

 cout << "Value of myNum:"<< myNum<<endl;

cout << "Value of PI is:"<< PI;

 return 0;

 } 

#include<iostream>
using namespace std;
#define myNum 10
#define PI 3.14
int main()
 {
cout<<"The value of myNum is:"<<myNum<<endl;
cout<<"The value of PI is:"<<PI<<endl;
return 0;
}

#include<iostream>
using namespace std;
int main()
 {
int constexpr Num = 26;
cout<<"The value of Num is:"<<Num;
return 0;
 } 

#include<iostream>
using namespace std;
int main() 
{
 //Decimal constant defined
const int decConstant = 802;

//Octal constant defined
const int octalConstant = 0732; 

//Hexadecimal constant defined
const int hexaConstant = 0x72C; 

//Printing all the Integer Constants

cout<<"Value of decimal constant is: "<<decConstant<<endl;

cout<<"Value of octal constant is: "<<octalConstant,<<endl;

cout<<"Value of Hexadecimal constant is: "<<hexaConstant;
    return 0;
} 

#include<iostream>
using namespace std;
int main() 
{ 
//Defining Floating Point Constant
const float PI = 3.14;
const float x = 4.6;

cout<<"The value of PI is:"<< PI<<endl;
cout<<"The value of x is:"<< x;
return 0;
 }

#include<iostream>
using namespace std;
int main() 
{ 
//Defining Character constant
const char myLetter = 'D';
const char digitChar = '7';

cout<<"Value of my-letter is:"<<myLetter<<endl;
cout<<"Value of digit-letter is:"<< digitChar;
return 0;
 }   

#include<iostream>
using namespace std;
int main() 
{ 
/Defining string constant
char myStr1[ ] ="Welcome to Computerehub";

char myStr2[ ] ="Here, we are learning string constant in C++";

cout<<myStr1<<endl;
cout<<myStr2;
return 0;
 }