Alexander Williams is a full stack developer and technical writer, with a background working as an independent IT consultant and helping new business owners set up their websites.
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JavaScript is an essential tool in the world of modern web development and continues to change and evolve to set new standards. In this article, we focus on five cutting-edge JavaScript techniques to show developers new and innovative ways to build dynamic web applications that offer high levels of interactivity and performance. From monads to pattern matching, we walk you through the latest and greatest JS techniques for advanced developers.
JavaScript has gained massive popularity due to its flexibility and has established itself as the world’s most widely used programming language. JS is often used to create dynamic web applications that feature a high level of interactivity — such as real-time updates, intuitive, feature-rich user interfaces, and much more. Furthermore, JavaScript allows applications to work across a range of platforms.
JS can be used for an array of projects, such as powering e-commerce services or producing animations and mobile games. However, this is just a snapshot of the programming language’s capabilities. We’re also seeing JS being used in enterprise environments, especially during key ERP-powered processes like SAP staff augmentation, as it allows for the creation of custom dashboards and UI, built on top of the native web platform.
Many leading platforms, like Facebook, use the open source user interface framework, React Native, which is built on JavaScript. This allows them to build mobile applications that work on both iOS and Android (and nowadays, even Apple Vision Pro) while using a single codebase. As a result, development times are significantly reduced, fewer resources are used, and the user experience is consistent across all platforms and devices.
Server-side runtime environments like Node.js make it possible to run JavaScript outside of a web browser, further increasing the scalability and deployment possibilities of applications. To make JS even more universal and versatile, a large number of JS-compatible APIs also link web applications to external services.
Finally, JavaScript is supported by a powerful ecosystem of libraries and frameworks that help simplify and speed up development, allowing developers to select pre-written code to perform specific functions.
We have selected five cutting-edge JavaScript techniques that developers should be using right now, to help you overcome numerous development issues and create more effective, user-friendly applications.
Monads help to compose functions that require context in order to return a value and are very effective at simplifying error management and reducing the likelihood of unexpected results.
Monads are all about making the composition of functions within code as simple as possible.
They are commonly used when constructing enterprise-level applications that require the utmost accuracy. Monads can make code more manageable, resulting in complex callbacks, nested conditional branches, and so on. In essence, monads are all about making the composition of functions within code as simple as possible.
Monads can be broken down into three types of function composition:
Function composition is the foundation that allows function pipelines to be created, allowing for efficient data flow. The first stage of the pipeline is input and the final stage is an output that has been transformed from its initial state. However, for this to work, every stage of the pipeline must be able to anticipate what data type the previous stage will return.
This is where monads come in, effectively mapping functions to create intelligent pipelines. They work in a similar way to promises and they can be seamlessly used together.
Here is an example of a monad being used to fetch a user from an asynchronous API, and then pass that user data to another asynchronous API to perform a calculation:
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const
composeM
=
chainMethod
=
>
(...
ms)
=
>
(
ms
.
reduce((
f,
g)
=
>
x
=
>
g(
x)[
chainMethod](
f))
);
const
composePromises
=
composeM(
'then');
const
label
=
'API call composition';
// a => Promise(b)
const
getUserById
=
id
=
>
id
===
3
?
Promise
.
resolve({
name:
'Kurt',
role:
'Author'
})
:
undefined;
// b => Promise(c)
const
hasPermission
=
({
role
})
=
>
(
Promise
.
resolve(
role
===
'Author')
);
// Compose the functions (this works!)
const
authUser
=
composePromises(
hasPermission,
getUserById);
authUser(
3).
then(
trace(
label));
// true
|
A declarative approach is often used when a developer prioritizes concise, expressive code.
Declarative programming in JavaScript focuses on the overall goals of the code and not how these goals are achieved. This makes code much more simple and readable — therefore, making it easier to maintain. A declarative approach is often used when a developer prioritizes concise, expressive code to deliver projects quickly.
Let’s compare a declarative approach to an imperative one:
Imperative:
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function
evenSum(
numbers)
{
let
result
=
0;
for
(
let
i
=
0;
i
<
numbers
.
length;
i++)
{
let
number
=
numbers[
i]
if
(
number
%
2
===
0)
{
result
+=
number;
}
}
return
result;
}
|
Declarative:
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3
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const
evenSum
=
numbers
=
>
numbers
.
filter(
i
=
>
i
%
2
===
0)
.
reduce((
a,
b)
=
>
a
+
b)
|
Server-side caching could be used to automate the scaling of resources based on usage metrics.
Caching is nothing new and may not be considered particularly cutting edge, but as both client-side and server-side web applications can use caching, it is a powerful tool for boosting performance. In particular, server-side caching can improve Node.js performance by speeding up data retrieval.
Let’s take a look at a simple example of the memory-cache technique in use:
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const
cache
=
require(
'memory-cache');
function
getDataFromCache(
key)
{
const
cachedData
=
cache
.
get(
key);
if
(
cachedData)
{
return
cachedData;
}
// If data is not in cache, fetch it from the source
const
data
=
fetchDataFromSource();
// Store data in cache for future use
cache
.
put(
key,
data,
60000);
// Cache for 60 seconds
return
data;
}
|
Server-side caching could be used to automate the scaling of resources based on usage metrics. AWS Lambda, Azure Functions, or Google Cloud Functions can be programmed to adjust services dynamically, while the AWS SDK for JavaScript allows you to monitor usage, optimize cloud costs and automate scaling actions, ensuring that you only pay for the resources you need.
Immutability refers to something that cannot be changed. In JavaScript (and programming in general) it refers to a value that can never be changed after it has been set. As applications are constantly changed and updated, immutability may seem unnecessary — but this is not the case.
This technique results in less debugging and fewer unexpected outcomes.
Data that cannot be changed is important because it helps to enable consistency through the code base and helps with state management. Instead of changing a value, a new one is created, making things more predictable and thus reducing errors — like those that occur when a data structure unexpectedly changes. This results in less debugging and fewer unexpected outcomes.
An example of immutability being used for name values:
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// Import stylesheets
import
'./style.css';
// Write JavaScript code!
const
appDiv
=
document
.
getElementById(
'app');
appDiv
.
innerHTML
=
`
<
h1
>
Open
the
console
to
see
results
</
h1
>`;
class
Person
{
//_name = "Nee";
//_name = ["Nee", "Ra"];
_name
=
{
first:
"Nee",
middle:
"L"
};
get
name()
{
return
this
.
_name;
}
set
name(
value)
{
console
.
log(
'In setter',
value);
this
.
_name
=
value;
}
}
let
p
=
new
Person();
//p.name = "Ra"; // Setter executes
//p.name.push("Lee"); // Setter doesn't execute
//p.name = [...p.name, "Lee"]; // Setter executes
//p.name.middle = "Lee"; // Setter doesn't execute
p
.
name
=
{
...
p
.
name,
middle:
"Lee"
};
// Setter executes
|
Immutability is a vital technique to know regardless of a developer’s specialism. This particular approach has been increasingly used in data science tasks and AI projects, proving once again that there are few tasks JavaScript is unable to tackle.
Pattern matching is a type of conditional branching that makes it possible to concisely match data structure patterns while binding variables simultaneously. Pattern matching is commonly used when writing XSLT stylesheets to transform XML documents.
Pattern matching is much more effective than the standard switch statement.
When it comes to testing a value against any given pattern, pattern matching is much more effective than the standard switch statement and provides much more control, allowing developers to write more complicated expressions.
Here is an example of the factorial function being implemented with the match module, using the JUnify library:
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match
=
function
()
{
var
unify
=
unification
.
unify;
function
match_aux(
patterns,
value)
{
var
i,
result;
for
(
i
=
0;
i
<
patterns
.
length;
i
+=
1)
{
result
=
unify(
patterns[
i][
0],
value);
if
(
result)
{
return
patterns[
i][
1](
result);
}
}
return
undefined;
}
return
function(
patterns,
value)
{
return
match_aux(
patterns,
value);
};
}();
var
fact
=
function
(
n)
{
return
match([
[
0,
function()
{
return
1;
}],
[$(
'n'),
function(
result)
{
return
result
.
n
*
fact(
result
.
n
-
1);
}]
],
n);
};
|
JavaScript is flexible, multifunctional, and can be deployed on a range of platforms. Using the above techniques means developers can create powerful but concise code for their applications.