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**

**Syntax: **

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`

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`// 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; ` ` ` `} ` |

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Output:

b1 is = 0 b2 is = 1 Yes 9

**Related article:** How to use Bool in C?

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