Logical Operators
As with comparison operators, you can also test for true or false values with logical operators.
Logical operators are used to determine the logic between variables or values, by combining multiple conditions:
| Operator | Name | Example | Description | Try it |
|---|---|---|---|---|
| && | AND | x < 5 && x < 10 | Returns 1 if both statements are true | |
| || | OR | x < 5 || x < 4 | Returns 1 if one of the statements is true | |
| ! | NOT | !(x < 5 && x < 10) | Reverse the result, returns 0 if the result is 1 |
Real-Life Example: Login Check
The example below shows how logical operators can be used in a real situation, e.g. when checking login status and access rights:
Example
int isLoggedIn = 1;
int isAdmin = 0;
printf("Regular user: %d\n", isLoggedIn && !isAdmin);
printf("Has access: %d\n", isLoggedIn || isAdmin);
printf("Not logged in: %d\n", !isLoggedIn);
Note: Remember: in C,
1means true and0means false. Logical operators often become easier to understand once you start using them insideifstatements, which you will learn about in the upcoming chapters.