How to Remove English Characters and Keep Only Foreign Unicode Characters with Kotlin

Learn how to effortlessly filter out English characters and punctuation from your text using Kotlin. This guide includes a practical example and a regex solution tailored for handling foreign Unicode characters.
---

Visit these links for original content and any more details, such as alternate solutions, comments, revision history etc. For example, the original title of the Question was: remove english characters and keep only foreign unicode characters

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Introduction

In programming and data manipulation, there might be instances where you need to isolate foreign characters while filtering out English letters and punctuation. This guide will provide you with an effective method to achieve this using Kotlin. Whether you're working with data files or processing user input, knowing how to handle foreign Unicode characters can greatly enhance your project.

The Issue

Imagine you have a text file filled with both English and foreign characters, but you only want to retain those foreign characters. You might be encountering a scenario like the following:

Raw Data Sample:

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

Expected Output:

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

The Solution

To navigate through this challenge, we will use Kotlin's powerful regex capabilities to strip away unwanted characters. Here's a step-by-step guide to achieve this.

Step 1: Set Up the Regex

We will utilize regex to match only the foreign Unicode characters while excluding ASCII characters. Here are two forms of regex that can be employed:

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

In both examples, the period . and space will be preserved with [^. ].

Step 2: Create an Extension Function

To make our solution reusable, we will implement an extension function for the File class. This function will read the text from the file and apply the regex to filter out English characters.

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

Step 3: Using the Function

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

This snippet reads the specified number of lines from the file and prints the foreign characters only.

Conclusion

With this approach, you can efficiently filter out English characters from your text and maintain the integrity of foreign unicode characters. Whether it's for data cleaning or processing, leveraging Kotlin's regex alongside its file handling capabilities can boost your productivity significantly. Now you're ready to tackle similar text processing challenges with confidence!