CPP

c++ declare variable

std::string str = "text";	// stores a string
int    foo = 3;				// stores any integer
float  bar = 3.14;			// stores 32 bit number
double baz = 3.14159265;	// stores 64 bit number

variables in c++

#include <iostream>
using namespace std;

int main() {
// To define variables in C++, you have to specify the data type. Example:
int number = 10; // Declares a variable with the integer data type.
float decimal = 3.5;  // Declares a variable with the float data type.
double decimalNum = 3.3333; // Doubles are used for more specific points in floats.
string text = "Hello World";  // Declares a variable with the string data type.
bool result = true;  // Declares a variable with the boolean data type.
  
}

what is a variable in cpp

Variable is simply a name or a label given to a memory location. 

C++ variables

// C++ program to show difference b/w definition and declaration of a variable
 
#include <iostream>
using namespace std;
 
int main()
{
      // this is declaration of variable a
      int a;
      // this is initialisation of a
      a = 10;
      // this is definition = declaration + initialisation
      int b = 20;
   
    // declaration and definition
    // of variable 'a123'
    char a123 = 'a';
 
    // This is also both declaration and definition
    // as 'c' is allocated memory and
    // assigned some garbage value.
    float c;
 
    // multiple declarations and definitions
    int _c, _d45, e;
 
    // Let us print a variable
    cout << a123 << endl;
 
    return 0;
}

declare a variable in cpp

// Syntax for Declaring a single variable
type variable_name;

// Syntax for Declaring multiple variables:
type variable1_name, variable2_name, variable3_name;

// Examples 

int a;
int x,y,z;

char c;
char c1,c2,c3;