input Property ($_)
Returns the string against which a regular expression search was performed.
//Syntax 1
{RegExp | reArray}.input
//Syntax 2
RegExp.$_
//The $_ property may be used as shorthand for the input property
//for the RegExp object.
Arguments
RegExp
Required. The global RegExp object.reArray
Required. An array returned by the exec method of a Regular Expression object.
Remarks
The value of input property is the string against which a regular expression search was performed.
The initial value of the RegExp.input property is an empty string, "". Its value is read-only and changes whenever a successful match is made.
Note
The properties of the RegExp object are not available when a program is running in fast mode, the default for JScript. To compile a program that uses these properties from a command prompt, you must turn off the fast option by using /fast-. It is not safe to turn off the fast option in ASP.NET because of threading issues.
Example
The following example illustrates the use of the input property:
var str = "A test string.";
var re = new RegExp("\\w+","ig");
var arr = re.exec(str);
print("The string used for the match was: " + arr.input);
The output of this program is:
The string used for the match was: A test string.