How Can Javascript Handle Null Values?

Null-Coalescing and Safe Navigation Operators in Javascript

In programming languages, the null-coalescing (Elvis) operator and safe navigation operator are used to handle null values gracefully.

Elvis Operator

The "Elvis operator" is not directly supported in Javascript. Instead, you can use the logical OR (||) operator to achieve a similar effect. For example:

<code class="js">const displayName = user.name || "Anonymous";</code>

This returns "Anonymous" if user.name is null, otherwise it returns the value of user.name.

Safe Navigation Operator

Javascript does not currently have a safe navigation operator. If you need to check for null before accessing a property or method, you must use explicit checks:

<code class="js">if (user && user.address && user.address.street) {
  const streetName = user.address.street;
}</code>

CoffeeScript provides a "wrapper functionality" that resembles the Elvis operator. The "Existential Operator" in CoffeeScript behaves as follows:

<code class="coffeescript">zip = lottery.drawWinner?().address?.zipcode</code>

If lottery.drawWinner() is null, the address and zipcode properties will not be accessed, and zip will be set to null.

In addition to the Elvis operator, CoffeeScript offers other syntactic shortcuts and alternative syntax that can enhance code brevity and readability. However, it's important to note that CoffeeScript code must be compiled to Javascript before it can be executed in a web browser.

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