JavaScript 2.0-The Complete Reference, Second ... - freecodingtutorial

also repeatedly apply this method to a string in order to step through the portions of the string
that match, one by one.
The exec() method accepts a string to match against, and it can be written shorthand by
directly invoking the name of the regexp as a function. For example, the two invocations in the
following example are equivalent:
var pattern = /http:.*/;pattern.exec("http://www.w3c.org/");pattern("http://www.w3c.org/");
The exec() method returns an array with a variety of properties. Included are the length of the
array; input, which shows the original input string; index, which holds the character index at
which the matching portion of the string begins; and lastIndex, which points to the character
after the match, which is also where the next search will begin. The script here illustrates the
exec() method and its returned values:
var pattern = /cat/;var result = pattern.exec("He is a big cat, a fat black cat named Rufus.");
document.writeln("result = "+result+"");
document.writeln("result.length = "+result.length+"");
document.writeln("result.index = "+result.index+"");
document.writeln("result.lastIndex = "+result.lastIndex+"");
document.writeln("result.input = "+result.input+"");
The result of this example is shown here:
The array returned may have more than one element if subexpressions are used. For example,
the following script has a set of three parenthesized subexpressions that are parsed out in the
array separately:
var pattern = /(cat) (and) (dog) /;
var result = pattern.exec("My cat and dog are black.");
document.writeln("result = "+result);
document.writeln("result.length = "+result.length);
document.writeln("result.index = "+result.index);