RegExp.lastMatch ($&)

The non-standard lastMatch property is a static and read-only property of regular expressions that contains the last matched characters. RegExp.$& is an alias for this property.

The lastMatch property is static, it is not a property of an individual regular expression object. Instead, you always use it as RegExp.lastMatch or RegExp['$&'].

The value of the lastMatch property is read-only and modified whenever a successful match is made.

You can not use the shorthand alias with the dot property accessor (RegExp.$&), because the parser expects an expression with "&" in that case and a SyntaxError is thrown. Use the bracket notation for property access.

var re = /hi/g;
re.test('hi there!');
RegExp.lastMatch; // "hi"
RegExp['$&'];     // "hi"

• RegExp.input ($_)
• RegExp.lastParen ($+)
• RegExp.leftContext ($`)
• RegExp.rightContext ($')
• RegExp.$1-$9