Скачать или смотреть Transforming key=value&... Strings with JavaScript

Learn how to change values in a `key=value&...` string using JavaScript with the `encodeURIComponent` function and object manipulation.
---
This video is based on the question https://stackoverflow.com/q/63925485/ asked by the user 'Stdugnd4ikbd' ( https://stackoverflow.com/u/6337792/ ) and on the answer https://stackoverflow.com/a/63926675/ provided by the user 'iAmOren' ( https://stackoverflow.com/u/5792509/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Change all values in string of format "key=value&..."

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Transforming Key-Value Strings in JavaScript

JavaScript developers often find themselves working with strings formatted as key=value&.... This format is commonly used in URLs and query parameters. If you have a string full of key-value pairs and need to change all the values (according to a specific rule), it can seem daunting at first. However, with a clear approach, you can efficiently manipulate these strings. In this guide, we'll explore a straightforward method to change the values of key-value combinations in such strings, particularly focusing on encoding values using encodeURIComponent.

Problem Overview

Suppose you have a string like the following:

[[See Video to Reveal this Text or Code Snippet]]

Your goal is to modify all of the values in this string using a function like encodeURIComponent. Below, we will break down the process into manageable steps, so you can easily follow along.

Step-by-Step Solution

1. Convert the String to an Object

To manipulate key-value pairs, a practical first step is to convert the query string into an object. This allows you to access and alter values easily.

Here's how to do it:

[[See Video to Reveal this Text or Code Snippet]]

Explanation:

Split the String: data.split("&") breaks the string into an array of key=value pairs.

Map Key-Value Pairs: The .map() function further splits each key=value string into an array [key, value].

Create an Object: Object.fromEntries(...) takes an array of key-value pairs and constructs an object.

2. Change Values Using encodeURIComponent

Once you have the object, it's straightforward to update the values. You can iterate through the object's keys and apply encodeURIComponent to each value.

Here's an example of how to do that:

[[See Video to Reveal this Text or Code Snippet]]

Explanation:

Iteration: The for..in loop goes through each key in the object.

Check Own Property: obj.hasOwnProperty(key) ensures that we only modify the properties that belong to the object itself.

Encode Values: By assigning encodeURIComponent(obj[key]), each value is now URL-encoded.

3. Convert the Object Back to String (if needed)

If you need to convert the object back to a string format, this can also be done easily:

[[See Video to Reveal this Text or Code Snippet]]

Explanation:

Object.entries(obj): This method retrieves the key-value pairs as an array of entries from the object.

Mapping Back to String: Each entry is transformed back into a key=value formatted string using template literals.

Joining Entries: The final .join("&") merges all the pairs into a single string.

Conclusion

By following these steps, you can efficiently manipulate key-value strings in JavaScript. From converting strings to objects, changing the values using encodeURIComponent, and then converting back to string format, this method provides a clear and effective solution to your problem.

Always remember to handle exceptions and edge cases, especially when working with user-generated input, to ensure robust code. Happy coding!