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

document.writeln("result.lastIndex = "+result.lastIndex);
document.writeln("result.input = "+result.input);
As you can see from the result,
the exec() method places the entire matched string in element zero of the array and any
substrings that match parenthesized subexpressions in subsequent elements.
exec() and the Global Flag
Sometimes you might wish to extract not just the first occurrence of a pattern in a string, but
each occurrence of it. Adding the global flag (g) to a regular expression indicates the intent to
search for every occurrence (i.e., globally) instead of just the first.
The way the global flag is interpreted by RegExp and by String is a bit subtle. In RegExp, it‘s
used to perform a global search incrementally, that is, by parsing out each successive
occurrence of the pattern one at a time. In String, it‘s used to perform a global search all at
once, that is, by parsing out all occurrences of the pattern in one single function call. We‘ll cover
using the global flag with String methods in the following section.
To demonstrate the difference between a regexp with the global flag set and one without,
consider the following simple example:
var lucky = "The lucky numbers are 3, 14, and 27";
var pattern = /\d+/;
document.writeln("Without global we get:");
document.writeln(pattern.exec(lucky));
document.writeln(pattern.exec(lucky));
document.writeln(pattern.exec(lucky));
pattern = /\d+/g;
document.writeln("With global we get:");
document.writeln(pattern.exec(lucky));
document.writeln(pattern.exec(lucky));