What is URL Encoding?​

URL encoding is the process of converting special characters and reserved characters in a URL to their corresponding encoded representation.

This encoding is necessary to ensure that URLs remain valid and don't break when passed as parameters or used in various parts of a web application.

How to encode url in Javascript?​

JavaScript provides a built-in function called encodeURIComponent() that performs URL encoding.

This function takes a string as input and returns a new string with all the necessary characters encoded. It ensures that characters like spaces, punctuation marks, and non-alphanumeric characters are appropriately encoded using percent encoding.

Example usage of encodeURIComponent() in JavaScript:

// Original string with special characters
var originalString = 'https://devzilla.org/urlencode/';

// URL-encode the string
var encodedString = encodeURIComponent(originalString);

// Output the encoded string
console.log(encodedString);

The output would be:

https%3A%2F%2Fdevzilla.org%2Furlencode%2F

How to decode url in Javascript?​

To decode a URL-encoded string in JavaScript, you can use the decodeURIComponent() function. This function reverses the encoding process and converts the encoded characters back to their original form.

Example usage of decodeURIComponent() in JavaScript:

// Encoded string
var encodedString = 'https%3A%2F%2Fdevzilla.org%2Furlencode%2F';

// URL-decode the string
var decodedString = decodeURIComponent(encodedString);

// Output the decoded string
console.log(decodedString);

The output would be:

https://devzilla.org/urlencode/

Is there a tools to encode and decode url online?​

Yes, there is:

https://devzilla.org/urlencode/

We have develop a tools so that you can quickly test encoding or decoding your url parameters. Use it any time, in your convenience!

Introduction:​

As JavaScript developers, we often works with arrays. The map function in JavaScript is a sugar syntax and a powerful tool that allows us to iterate over array elements and perform transformations easily. In this 1 minute guide, we will explore the map function, understand why it is preferred over traditional array loops, and provide a code example to illustrate its usage.

How to use the Map Function in Javascript​

The Map Function​

The map function is a higher-order function available on JavaScript arrays. It takes a callback function as an argument and applies that function to each element of the array, creating a new array with the transformed values.

Syntax:

array.map(callback[, thisArg])

Parameters:

• callback: A function that will be called for each element in the array. It can take three arguments:
  • currentValue: The current element being processed in the array.
  • index (optional): The index of the current element being processed.
  • array (optional): The original array that the map() function was called upon.

Return Value:

The map() function returns a new array with the results of calling the provided callback function on each element of the original array.

Exceptions:

The map() function does not throw any exceptions. However, it is important to note that the callback function provided to map() might throw an exception if there is an error within the callback logic. It's recommended to handle any potential exceptions within the callback function or in the surrounding code if necessary.

Example using map() in your code​

Given we're having an array:

const numbers = [1, 2, 3, 4, 5];

To use map function, we just need to call the map() function on the numbers array:

const squaredNumbers = numbers.map((num) => {
  return num ** 2;
});

In that case, the output of squaredNumbers:

console.log(squaredNumbers);

will be:

[1, 4, 9, 16, 25]

Why use map function over array loops​

Let's compare the traditional approach of looping through an array with the usage of the map() function. Consider a scenario where we have an array of numbers and want to create a new array with each number squared.

Using a loop:

// Original array
const numbers = [1, 2, 3, 4, 5];

// Loop through the array and square each number
const squaredNumbers = [];
for (let i = 0; i < numbers.length; i++) {
  squaredNumbers.push(numbers[i] ** 2);
}

// Output the squared numbers
console.log(squaredNumbers);

Using the map() function:

// Original array
const numbers = [1, 2, 3, 4, 5];

// Map function to square each number
const squaredNumbers = numbers.map((num) => num ** 2);

// Output the squared numbers
console.log(squaredNumbers);

Output (for both approaches):

[1, 4, 9, 16, 25]

In the above code examples, we have an array numbers containing five elements. In the first approach, we use a for loop to iterate through the array, square each number, and push it to a new array squaredNumbers. In the second approach, we utilize the map() function, passing a callback function (num) => num ** 2 to square each number. The resulting arrays, squaredNumbers, contain the squared values. Both approaches produce the same output.