Bool Data Type In C++ - Definition

Bool Data Type In C++ - Definition

The ISO/ANSI C++ Standard has added certain new data types to the original C++ specifications.They are provided to provide better control in certain situations as well as for providing conveniences to C++ programmers.
One of the new data type is: bool

bool b1 = true;      // declaring a boolean variable with true value  

In C++, the data type bool has been introduced to hold a boolean value, true or false. The values true or false have been added as keywords in the C++ language.

Important Points: 

• The default numeric value of true is 1 and false is 0.
• We can use bool type variables or values true and false in mathematical expressions also.For instance,

  int x = false + true + 6; 

  is valid and the expression on right will evaluate to 7 as false has value 0 and true will have value 1.
• It is also possible to convert implicitly the data type integers or floating point values to bool type. For example, the statements-

  bool x = 0;  // false bool y = 100;  // true bool z = 15.75;  // true

// CPP program to illustrate bool 

// data type in C++

#include<iostream>

using namespace std;

int main()

{

    int x1 = 10, x2 = 20, m = 2;

    bool b1, b2;

    b1 = x1 == x2; // false

      

    b2 = x1 < x2; // true

      

    cout << "b1 is = " << b1 << "\n";

    cout << "b2 is = " << b2 << "\n";

    bool b3 = true;

      

    if (b3)

        cout << "Yes" << "\n";

    else

        cout << "No" << "\n";

          

    int x3 = false + 5 * m - b3;

    cout << x3;

      

return 0;

      

} 

Output:

b1 is = 0
b2 is = 1
Yes
9