RegExp.prototype.source

The source property returns a String containing the source text of the regexp object, and it doesn't contain the two forward slashes on both sides and any flags.

Property attributes of RegExp.prototype.source
Writable no
Enumerable no
Configurable yes

Examples

Using source

var regex = /fooBar/ig;

console.log(regex.source); // "fooBar", doesn't contain /.../ and "ig".

Empty regular expressions and escaping

Starting with ECMAScript 5, the source property no longer returns an empty string for empty regular expressions. Instead, the string (?:) is returned. In addition, line terminators (such as "\n") are escaped now.

new RegExp().source; // "(?:)"

new RegExp('\n').source === '\n';  // true, prior to ES5
new RegExp('\n').source === '\\n'; // true, starting with ES5

Specifications

Specification
ECMAScript Language Specification
# sec-get-regexp.prototype.source

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
ChromeEdgeFirefoxInternet ExplorerOperaSafariWebView AndroidChrome AndroidFirefox for AndroidOpera AndroidSafari on iOSSamsung InternetDenoNode.js
source
"(?:)" for empty regexps
Escaping
Prototype accessor property (ES2015)

Legend

Full support
Full support
No support
No support

See also