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Destruction and function arguments

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The JavaScript language has enjoyed many great new features in recent years, including arrow functions, the spreading operator and standard argumentation values. Even if your browser does not yet support suggested JavaScript syntax refills, you can use a tool like Babel in your Node.js app to take advantage of it today.

One of my favorite new (ish) JavaScript functions is object destruction. If you are not familiar with JavaScript destructuring, this actually provides a shorter syntax for extracting the value of a object key without the dot notation:

// A sample object
const myObject = ;

// Destructuring
const  = myObject;
// x is 1, y is 2

The basic syntax for destructuring is fairly simple, but the use of destructuring with function arguments can be a bit more difficult if those argument values ​​have to have default values. The following is a function with arguments with default values:

function myFunction (text = "", line = 0, truncate = 100)  0;
truncate = truncate 

Regardless of the language, if a function requires more than ~ 3 parameters, it is probably best to pass an object name options or config to that possible key / contains values; the equivalent would look like:

function myFunction (config) 

// Use
myFunction ()

What if you want to use destructuring in JavaScript function arguments? The next signature of the function would be:

function myFunction () 

To define default settings in the function configuration, use the following:

function myFunction ( = ) 

Setting a standard with = is important; without default the following example would give an error message:

TypeError: property & # 39; key & # 39; from & # 39; undefined & # 39; or & # 39; null & # 39; can not be destroyed

Destructures is a great language function but can lead to confusion and even to mistakes. Hopefully the basics in this guide can help you navigate with JavaScript destructuring with features!


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