RetroSearch Browse

Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from https://www.geeksforgeeks.org/javascript-regexp-unicode-property/ below:

JavaScript RegExp unicode Property - GeeksforGeeks

JavaScript RegExp unicode Property

Last Updated : 05 Aug, 2025

The unicode property of a JavaScript regular expression object indicates whether the u (Unicode) flag is enabled. When this flag is set, the regular expression operates in full Unicode mode, allowing correct handling of Unicode characters, such as surrogate pairs, Unicode code points, and properties.

JavaScript


 // Regular expression without 'u' flag
let regex1 = /\u{1F600}/; 
console.log(regex1.unicode); 

// Regular expression with 'u' flag
let regex2 = /\u{1F600}/u; 
console.log(regex2.unicode);

regex1 does not treat \u{1F600} as a Unicode code point.
regex2 recognizes \u{1F600} as a valid Unicode code point (😀 emoji).

Syntax:

regex.unicode

Key Points

Read-Only: The unicode property is read-only and reflects whether the u flag is set.
Unicode Awareness: Patterns use Unicode code points instead of individual UTF-16 units.
Surrogate Pair Handling: Correctly matches characters represented by surrogate pairs (e.g., emojis).
Property Escapes: Enables use of Unicode property escapes (e.g., \p{...}).

Real-World Examples 1. Matching Unicode Code Points JavaScript


 // Emoji 😀 (code point U+1F600)
let regex = /\u{1F600}/u;
console.log(regex.test("😀")); 
console.log(regex.test("smile"));

The u flag ensures the pattern correctly matches the full Unicode code point.

2. Using Unicode Property Escapes JavaScript


 let regex = /\p{Script=Greek}/u;
console.log(regex.test("α")); 
console.log(regex.test("a"));

The u flag enables matching based on Unicode properties like script, block, or general categories.

3. Handling Surrogate Pairs JavaScript


 let s = "😀";
// Emoji stored as a surrogate pair in UTF-16
let regex = /[\uD83D\uDE00]/;
 // Matches the individual UTF-16 units
let regexUnicode = /\u{1F600}/u; 
// Matches the full code point
console.log(regex.test(s)); 
console.log(regexUnicode.test(s));

Without the u flag, matching surrogate pairs requires specifying both UTF-16 units.

4. Differentiating Characters and Code Points JavaScript


 let regex = /^.$/;
let regexUnicode = /^.$/u;

console.log(regex.test("😀")); 
console.log(regexUnicode.test("😀"));

The u flag ensures that . matches a full Unicode character, not just a single UTF-16 code unit.

5. Combining Property Escapes with Other Patterns JavaScript


 let regex = /\p{L}\d+/u;
// Match letters followed by digits
console.log(regex.test("A123"));
console.log(regex.test("1A23"));

The u flag makes advanced Unicode patterns like property escapes possible.

Why Use the unicode Property?

Unicode Compliance: Ensures regex patterns handle all Unicode characters, including emojis and complex scripts.
Accurate Matching: Prevents misinterpretation of surrogate pairs and ensures correct handling of full code points.
Advanced Features: Enables Unicode property escapes for precise matching of scripts, blocks, and categories.

Conclusion

The unicode property is essential for working with modern text containing diverse Unicode characters, ensuring accuracy and consistency in JavaScript regular expressions.

Recommended Links:

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4