Full-Width Katakana Check Using Javascript

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In this blog post, we will discuss how to check if a string contains full-width katakana characters using JavaScript. Full-width katakana characters are used in Japanese text and take up twice as much space as regular characters. We will go over the steps to create a function that can detect these characters in a string.

What are full-width katakana characters?

Full-width katakana characters are a set of Japanese characters that are twice the width of standard characters. They are often used for emphasis or to create a unique visual style. You can use them in Slack by typing the character in between two double-byte spaces. For example, to type the full-width katakana character for “ka”, you would type ‘ カ ‘.

Why is it important to check for full-width katakana characters?

It is important to check for full-width katakana characters because full-width characters are double-byte and require twice as much storage space as half-width katakana characters. Legacy systems built with half-width katakana characters do not have the storage space to store double by characters. Additionally, katakana characters are used primarily in matching people’s names and addresses, double byte characters cannot be matched properly with single byte characters.

Full-width Katakana checking using unicode regular expression matching

To validate for full-width katakana characters using JavaScript using unicode character codes, you can use the following regular expression:

const regex = /^[\u30A0-\u30FF]+$/;

This regular expression matches any string that contains only full-width katakana characters. You can use it with the test() method to check if a string matches the pattern:

const str = 'アイウエオ';
const isValid = regex.test(str); // true

You can also use it with the match() method to extract all full-width katakana characters from a string:

const str = 'カタカナ is a Japanese katakana';
const matches = str.match(regex); // ['カタカナ']

Try Full-Width Katakana Check