Passing In Null As A Parameter In Es6 Does Not Use The Default Parameter When One Is Provided

When you're working in ES6 and dealing with default parameters, you might run into a situation where passing in `null` as a parameter doesn't behave as you'd expect. This can be a bit puzzling, but don't worry, I've got you covered!

Let’s dive into understanding this issue. In ES6, default parameters allow you to specify default values for function parameters. When a parameter is not provided or is `undefined`, the default value kicks in. However, the behavior can be unexpected when you explicitly pass in `null`.

Here's an example to illustrate this behavior:

function myFunction(param = 'default') {
    console.log(param);
}

myFunction(null); // Output: null

In this example, even though we are passing `null` explicitly to the function, it logs `null` instead of using the default value. This happens because in JavaScript, `null` is considered a valid value – it represents the absence of any object value.

So, how can you work around this behavior if you want to enforce the default value when `null` is passed? One approach is to use a conditional statement inside the function:

function myFunction(param) {
    if (param === null) {
        param = 'default';
    }
    console.log(param);
}

myFunction(null); // Output: default

By explicitly checking for `null` within the function, you can override the provided value with the default one when needed. This ensures that your function behaves as intended even when `null` is passed.

Another workaround is to leverage the logical OR operator (`||`) in ES6 to achieve the desired result:

function myFunction(param = 'default') {
    param = param || 'default';
    console.log(param);
}

myFunction(null); // Output: default

In this version, the logical OR operator checks if `param` evaluates to a truthy value. If `param` is `null`, it defaults to `'default'`, ensuring the expected behavior.

Understanding these nuances of default parameters and handling `null` values can save you from unexpected behaviors in your ES6 functions. By incorporating these techniques into your code, you can write more robust and predictable functions.

Remember, mastering the intricacies of JavaScript can make your coding journey smoother and more enjoyable. Stay curious, keep exploring, and don't hesitate to reach out if you have more questions or need further clarification.

Happy coding!