C++ Booleans (original) (raw)

Last Updated : 14 Oct, 2025

Boolean (bool) is a data type that can store only two values: true or false. It is used to represent logical conditions or binary states in a program.

• Internally, true is represented as 1 and false as 0, so boolean values can be used in arithmetic expressions.
• Integer or floating-point values can be implicitly converted to bool (0 becomes false and any non-zero value becomes true). C++ `

#include using namespace std;

int main() { int a = 10, b = 20;

// Boolean variables
bool isEqual = (a == b);
bool isSmaller = (a < b);

cout << "Is a equal to b? " << isEqual << endl;
cout << "Is a smaller than b? " << isSmaller << endl;

// Using bool in if statement
if (isSmaller) 
    cout << "a is smaller than b" << endl;
else 
    cout << "a is not smaller than b" << endl;

return 0;

}

`

Output

Is a equal to b? 0 Is a smaller than b? 1 a is smaller than b

Important Points

**1. The default numeric value of _true is **1 and false is **0.

**2. We can use bool-type variables or values _true and _false in mathematical expressions also. For instance,

_int x = false + true + 6;

It is valid and the expression on the right will evaluate to **7 as _false has a value of 0 and _true will have a value of 1.

**3. It is also possible to convert implicitly the data type integers or floating point values to bool type.

**Example:

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

**5. The most common use of the bool datatype is for conditional statements. We can compare conditions with a boolean, and also return them telling if they are true or false.