Logical operators can be combined to form expressions containing multiple conditions. Parentheses can be used to explicitly control how the conditions are grouped.

#include <stdio.h>

int main()
{
    int age = 25;
    int has_id = 1;
    int has_permission = 0;

    if ((age >= 18 && has_id) || has_permission)
    {
        printf("Access granted\n");
    }

    return 0;
}

Example Output #

Access granted

Explanation #

The condition contains both && and ||:

(age >= 18 && has_id) || has_permission

The expression is grouped as:

(age >= 18 && has_id)

and:

has_permission

The first group is true because age >= 18 is non-zero and has_id is also non-zero. Therefore, the || expression is true, regardless of the value of has_permission.

Parentheses make the intended grouping explicit. Without parentheses, && has higher precedence than ||, so an expression such as:

a || b && c

is evaluated as:

a || (b && c)