The standard language for creating contemporary online and mobile applications is JavaScript. It is used to power many different applications, from straightforward websites to dynamic, interactive apps.
You must build code that is not just functional but also effective and simple to maintain if you want to develop things that people will like. Whether it's a little side project for fun or a sophisticated commercial application, clean JavaScript code is essential for the success of any online or mobile application.
JavaScript Functions
Writing code for every application requires the use of functions. It specifies a section of reusable code that you may use to carry out a certain activity.
Functions are extremely flexible in addition to being reusable. In the long term, they make growing and maintaining a codebase simpler. You may cut down on the amount of time spent developing by generating and utilising JavaScript functions.
Here are a few useful JavaScript functions that will assist your project's code to be much better.
1. map
A method of the default JavaScript Array class is the map function. By calling a callback function on each element of the initial array, it generates a new array.
Every element in the input array is looped over, sent to the callback function as input, and then each result is added to a new array.
It's crucial to keep in mind that nothing about the original array is changed throughout this procedure.
This is an illustration of how to utilize a map:
const numbers = [1, 2, 3, 4, 5];
const doubledNumbers = numbers.map(function(number) {
return number * 2;
});
console.log(doubledNumbers);
// Output: [2, 4, 6, 8, 10]
The map function iterates through each item in the numbers array in this example. Each element is multiplied by two, and the results are returned in a new array.
In general, map functions replace the need for loops in JavaScript, especially endless ones, which may have a major negative impact on an application's speed. The codebase becomes cleaner and less prone to mistakes as a result.
2. once
This higher-order once function covers a different function to prevent multiple calls to it. Any further attempts to invoke the resultant function should be quietly rejected.
Think of a scenario where you wish to use the HTTP API to request data from a database. The once function can be added as a callback to an event listener function, causing it to only be triggered once.
You might define such a function as follows:
const once = (func) => {
let result;
let funcCalled = false;
return (...args) => {
if (!funcCalled) {
result = func(...args);
funcCalled = true;
}
return result;
};
};
A function is sent to the once function, which returns a new function that can only be called once. The new function performs the original function with the supplied parameters the first time it is called, saving the outcome.
The stored result is returned in response to any subsequent calls to the new function without having to call the previous one again.
See the following implementation:
// Define a function to fetch data from the DB
function getUserData() {
// ...
}
// get a version of the getUserData function that can only run once
const makeHTTPRequestOnlyOnce = once(getUserData);
const userDataBtn = document.querySelector("#btn");
userDataBtn.addEventListener("click", makeHTTPRequestOnlyOnce);
Even if the user hits the button many times, utilizing the once method ensures that the code only makes one request. By doing this, performance problems and defects that may arise from repeated queries are avoided.
3. zip
The zip function matches corresponding entries from each input array to create a single array of tuples.
Here is an illustration of how a zip function is implemented:
function zip(...arrays) {
const maxLength = Math.min(...arrays.map(array => array.length));
return Array.from(
{ length: maxLength },
(_, index) => arrays.map(array => array[index])
);
};
const a = [1, 2, 3];
const b = ['a', 'b', 'c'];
const c = [true, false, true];
console.log(zip(a, b, c));
// Output: [[1, 'a', true], [2, 'b', false], [3, 'c', true]]
The zip function determines the largest length of input arrays. After that, it uses the JavaScript function Array.from to generate and return a single array. Element data from each input array is contained in this new array.
This saves you from having to create extraneous code that might otherwise clutter your codebase and is especially helpful if you need to rapidly merge data from several sources.
4. pipe
You may link many functions together in a row using the pipe function. The functions in the order will use the output of the function before them as input, and the last function will compute the outcome.
Here is a code illustration:
// Define the pipe function
const pipe = (...funcs) => {
return (arg) => {
funcs.forEach(function(func) {
arg = func(arg);
});
return arg;
}
}
// Define some functions
const addOne = (a) => a + 1;
const double = (x) => x * 2;
const square = (x) => x * x;
// Create a pipe with the functions
const myPipe = pipe(addOne, double, square);
// Test the pipe with an input value
console.log(myPipe(2)); // Output: 36
By enabling you to condense complicated processing logic, pipe functions can increase the readability and modularity of your code. Your code may become easier to read and maintain as a result.
5. pick
With the help of this chosen method, you may pick out particular characteristics from an existing object and use those properties to create a new object.
Consider a feature in an application that allows you to create reports. By using the chosen method, you can easily tailor multiple reports based on the needed user information by explicitly stating the attributes that you want to include in different reports.
Here's an example in code:
const pick = (object, ...keys) => {
return keys.reduce((result, key) => {
if (object.hasOwnProperty(key)) {
result[key] = object[key];
}
return result;
}, {});
};
An object and any quantity of keys are accepted as inputs for the pick function. The attributes you wish to choose are represented by the keys. Then, a new object is returned that only has the original object's properties with matching keys.
const user = {
name: 'Martin',
age: 30,
email: 'Martin@yahoo.com',
};
console.log(pick(user, 'name', 'age'));
// Output: { name: 'Martin', age: 30 }
In essence, a choose function may condense complicated filtering logic into a single function, simplifying the code and facilitating debugging.
Since you may reuse the pick method across your whole codebase, it can help encourage code reuse by minimizing code duplication.
Use JavaScript Functions in Your Code
JavaScript functions offer a streamlined and condensed solution to manage a lot of the programming logic for both small and big codebases, considerably enhancing the quality of your code. You may create programs that are more effective, readable, and manageable by comprehending and utilizing these features.
Building solutions that not only solve a specific problem for end customers but also do it in a way that is simple to alter, is made feasible by writing good code.