Functions and Their Importance in Code
Tags: webdev, beginners
Published: 2023-05-14 23:04:09

As my Flatiron Bootcamp has taught me, **"Functions are the single most important unit of code in JavaScript."** Functions are one of the most important concepts and useful tools for any programmer to use today. Some however, like me, will find the concepts a bit tricky in the beginning. So what are they? They are the building blocks of any program and are used extensively, especially in web development. While they're used in most programming languages, I'll be exploring them using Javascript. 

What are functions?

A function is a block of code that performs a specific task. It is a reusable piece of code that can be called from other parts of the program. This makes the code reusable and clean. Also making it more manageable. We can execute or call functions multiple times.

Functions in JavaScript are structured using the "function" keyword, followed by the function name, and the parameters enclosed in parentheses. The code that is executed when the function is called is enclosed in curly braces. Here's an example:


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/z77uep42cd7besayg8uv.png)


In this example, the function is named "greet", and it takes a single parameter called "name". When the function is called, it will log a message to the console, using the parameter that was passed to the function.

So are their different types of functions? There are two types of functions in JavaScript: named functions and anonymous functions.

Named functions are functions that are given a name when they are defined. Here's an example:


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/3spw58a23ve94bfk0jvc.png)


In this example, the function is named "sum". It takes two parameters, "a" and "b", and returns the sum of the two numbers.
The previous example was also the same as it has the name greet and passes one parameter. 

Anonymous functions are functions that do not have a name. Instead, they are assigned to a variable directly. Here's an example:


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/7kcf8zd8ltl3q3go0ctu.png)


In this example, the function is assigned to a variable called "multiply". It takes two parameters, "a" and "b", and returns the product of the two numbers. To better understand this, you ca relate it to multiply being the name of a function taking a and b as the parameters. 

Best Practices for Functions in JavaScript

Here are some things to look out for with functions.

Always declare functions before using them - named functions in JavaScript are hoisted, which means that they are moved to the top of the code. However, anonymous functions are not hoisted which means they must be declared first, then call/used. 

Use meaningful function names - Giving functions descriptive names can make your code more readable and easier to understand.

Use parameters effectively - Functions can take zero or more parameters. Use parameters effectively to make your code more flexible and reusable.

Use return statements - Functions can return values using the "return" keyword. Use return statements to pass values back to the calling code. This is important as sometimes the function runs perfectly but doesn't return the result as it's missing the return keyword.  

Here is another way to write a function. Arrow functions are a shorthand way of defining functions in JavaScript. They can make your code more concise and readable. Usually even in one single line if the body is short. 

Here's an example of an arrow function:


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/7abg69awlzt610u4wrnp.png)


In this example, the function is defined using an arrow function. It takes a single parameter called "name" and logs a message to the console. Again it can be said that the greet represents the name of the function and it's accepting one parameter. 

In Conclusion

Functions are an important concept to learn and master in any programming language, especially in my case with JavaScript. They help to modularize code and make it more manageable. They're reusable and easy to read when written well. By following best practices when working with functions in JavaScript, you can write better, effienct, and easy to read code.