Fedor Skrynnikov Fedor Skrynnikov - 14 days ago 6
Javascript Question

replace emoji unicode symbol using regexp in javascript

As you all know emoji symbols are coded up to 3 or 4 bytes, so it may occupy 2 symbols in my string. For example '

Answer

The \u.... notation has four hex digits, no less, no more, so it can only represent code points up to U+FFFF. Unicode characters above that are represented as pairs of surrogate code points.

So some indirect approach is needed. Cf. to JavaScript strings outside of the BMP.

For example, you could look for code points in the range [\uD800-\uDBFF] (high surrogates), and when you find one, check that the next code point in the string is in the range [\uDC00-\uDFFF] (if not, there is a serious data error), interpret the two as a Unicode character, and replace them by whatever you wish to put there. This looks like a job for a simple loop through the string, rather than a regular expression.