bennadel/clone-regexp.htm

## clone-regexp.htm
<!doctype html>
<html>
<head>
	<title>Cloning RegExp (Regular Expression) Objects In JavaScript</title>
</head>
<body>

	<script type="text/javascript">

		/**
		* I clone the given RegExp object, and ensure that the given flags exist on
		* the clone. The injectFlags parameter is purely additive - it cannot remove
		* flags that already exist on the
		*
		* @input RegExp - I am the regular expression object being cloned.
		* @injectFlags String( Optional ) - I am the flags to enforce on the clone.
		*/
		function cloneRegExp( input, injectFlags ) {

			var pattern = input.source;
			var flags = "";

			// Make sure the parameter is a defined string - it will make the conditional
			// logic easier to read.
			injectFlags = ( injectFlags || "" );

			// Test for global.
			if ( input.global || ( /g/i ).test( injectFlags ) ) {

				flags += "g";

			}

			// Test for ignoreCase.
			if ( input.ignoreCase || ( /i/i ).test( injectFlags ) ) {

				flags += "i";

			}

			// Test for multiline.
			if ( input.multiline || ( /m/i ).test( injectFlags ) ) {

				flags += "m";

			}

			// Return a clone with the additive flags.
			return( new RegExp( pattern, flags ) );

		}


		// -------------------------------------------------- //
		// -------------------------------------------------- //


		var regex = new RegExp( "http://www.bennadel.com", "i" );

		// Clone the regular expression object, but ensure "g" (global) flag is set
		// (even if it was not set on the given RegExp instance).
		var clone = cloneRegExp( regex, "g" );

		// The clone should now have both the "i" (source) and "g" (injected) flags set.
		console.log( "Clone:", clone );

	</script>
</body>
</html>
	<!doctype html>
	<html>
	<head>
	<title>Cloning RegExp (Regular Expression) Objects In JavaScript</title>
	</head>
	<body>

	<script type="text/javascript">

	/**
	* I clone the given RegExp object, and ensure that the given flags exist on
	* the clone. The injectFlags parameter is purely additive - it cannot remove
	* flags that already exist on the
	*
	* @input RegExp - I am the regular expression object being cloned.
	* @injectFlags String( Optional ) - I am the flags to enforce on the clone.
	*/
	function cloneRegExp( input, injectFlags ) {

	var pattern = input.source;
	var flags = "";

	// Make sure the parameter is a defined string - it will make the conditional
	// logic easier to read.
	injectFlags = ( injectFlags \|\| "" );

	// Test for global.
	if ( input.global \|\| ( /g/i ).test( injectFlags ) ) {

	flags += "g";

	}

	// Test for ignoreCase.
	if ( input.ignoreCase \|\| ( /i/i ).test( injectFlags ) ) {

	flags += "i";

	}

	// Test for multiline.
	if ( input.multiline \|\| ( /m/i ).test( injectFlags ) ) {

	flags += "m";

	}

	// Return a clone with the additive flags.
	return( new RegExp( pattern, flags ) );

	}


	// -------------------------------------------------- //
	// -------------------------------------------------- //


	var regex = new RegExp( "http://www.bennadel.com", "i" );

	// Clone the regular expression object, but ensure "g" (global) flag is set
	// (even if it was not set on the given RegExp instance).
	var clone = cloneRegExp( regex, "g" );

	// The clone should now have both the "i" (source) and "g" (injected) flags set.
	console.log( "Clone:", clone );

	</script>
	</body>
	</html>