Webflags: g

HTML Entity

Match HTML entities in named (`&`), numeric (`{`), or hex (`💩`) form.

Available in

JavaScript / ECMAScript code

jsJavaScript

const re = new RegExp("&(?:[a-zA-Z][a-zA-Z0-9]+|#\\d+|#x[0-9a-fA-F]+);", "g");
const input = "Tom &amp; Jerry &lt;3";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));

Uses `String.prototype.matchAll` for global iteration (Node 12+ / all modern browsers).

Python (re) code

pyPython

import re

pattern = re.compile(r"&(?:[a-zA-Z][a-zA-Z0-9]+|#\d+|#x[0-9a-fA-F]+);")
input_text = "Tom &amp; Jerry &lt;3"
for m in pattern.finditer(input_text):
    print(m.group(0))

Stdlib `re` module — no third-party dependency. Works on Python 3.6+.

Go (RE2) code

goGo

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`&(?:[a-zA-Z][a-zA-Z0-9]+|#\d+|#x[0-9a-fA-F]+);`)
	input := `Tom &amp; Jerry &lt;3`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.

Pattern

regexengine-agnostic

&(?:[a-zA-Z][a-zA-Z0-9]+|#\d+|#x[0-9a-fA-F]+);   (flags: g)

Raw source: &(?:[a-zA-Z][a-zA-Z0-9]+|#\d+|#x[0-9a-fA-F]+);

How it works

The leading `&` and trailing `;` bracket the entity. The middle alternation matches: a named entity ([a-zA-Z][a-zA-Z0-9]+ — letters then alphanumerics, like `amp`, `lt`, `nbsp`); a decimal entity (#\d+, like `#160`); or a hex entity (#x[0-9a-fA-F]+, like `#xA0` or `#x1F600` for emoji).