This rule raises an issue when a function call result is used, even though the function does not return anything.

## Why is this an issue?

If a function does not return anything, it makes no sense to use its output. Specifically, passing it to another function, or assigning its "result" to a variable is probably a bug because such functions return nothing, which is probably not what was intended.

### Code examples

#### Noncompliant code example

    $result = closedir($dir_handle); // Noncompliant, "closedir" does not return anything.

#### Compliant solution

    closedir($dir_handle);

## Resources

### Documentation

- PHP documentation - Returning values