The result of this code is `11`. When the function is called with `add(5)`, the parameter `x` gets the value 5. Since no value is provided for `y`, its default value is calculated as `x + 1`, which is 5 + 1 = 6. The function then returns `x + y`, which is 5 + 6 = 11. This example demonstrates how default parameters can be expressions that reference earlier parameters, allowing for dynamic defaults based on other inputs. This capability enables powerful patterns like creating related values, maintaining proportional relationships between parameters, or implementing more complex defaulting logic that goes beyond simple static values. It's important to remember that this only works for parameters that appear earlier in the parameter list, as the parameters are processed from left to right.