### Boolean Data Type ?

The "boolean" data type is used to represent boolean values that returns either "true" or "false". Where in, value `'1'` returns true and value `'0'` returns false.

### Boolean data type :

Boolean variables are variables that can have only two possible values: true, and false.

To declare a Boolean variable, we use the keyword bool.

`         `bool b;``

To initialize or assign a true or false value to a Boolean variable, we use the keywords true and false.

```         ```bool b1 { true };
bool b2 { false };
b1 = false;``````

Boolean values are not actually stored in Boolean variables as the words “true” or “false”. Instead, they are stored as integers: true becoms the integer 1, and false becoms the integer 0.

```
1
0
0
1
```

### Example 2:

```#include <stdio.h>
#include <stdbool.h>

int main(void)
{
bool a=true, b=false;
printf("%d\n", a&&b);
printf("%d\n", a||b);
printf("%d\n", !b);
}
```

```
0
1
1
```

### Example 3:

```// 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
```