You can even nest <c:forEach> tags

What if you have something like a collection of collections? An array of arrays? You can nest <c:forEach> tags for more complex table structures. In this example, we put String arrays into an ArrayList, then make the ArrayList a request attribute. The JSP has to loop through the ArrayList to get each String array, then loop through each String array to print the actual elements of the array.

Servlet code

String[] movies1 = {"Matrix Revolutions", "Kill Bill", "Boondock Saints"};
String[] movies2 = {"Amelie", "Return of the King", "Mean Girls"};
java.util.List movieList = new java.util.ArrayList();
movieList.add(movies1);
movieList.add(movies2);
request.setAttribute("movies", movieList);

JSP code

There are no Dumb Questions

Q:
Q: How did you know that the “varStatus” attribute was an instance of whatever that was, and how did you know that it has a “count” property?
A:
A: Ahhhh... we looked it up.
It’s all there in the JSTL 1.1 spec. If you don’t have the spec already, go download it NOW (the intro of this book tells you where to get the specs covered on the exam). It is THE reference for all the tags in the JSTL, and tells you all the possible attributes, whether they’re optional or required, the attribute type, and any other details on how you use the tag.
Everything you need to know about these tags (for the exam) is in this chapter. But some of the tags have a few more options than we cover here, so you might want to have a look in the spec.
Q:
Q: Since you know more than you’re telling about this tag... does it give you a way to change the iteration steps? In a real Java for loop, I don’t have to do i++, I can do i +=3, for example, to get every third element instead of every element...
A:
A: Not a problem. The <c:forEach> tag has optional attributes for begin, end (in case you want to iterate over a subset of the collection), and step if you want to skip over some elements.
Q:
Q: Is the “c” in <c:forEach> a required prefix?
A:
A: Well, some prefix is required, of course; all tags and EL functions must have a prefix to give the Container the namespace for that tag or function name. But you don’t HAVE to name the prefix “c”. It’s just the standard convention for the set of tags in JSTL known as “core”. We recommend using something other than “c” as a prefix, whenever you want to totally confuse the people you work with.

Watch it!

The “var” variable is scoped to ONLY the tag!

That’s right, tag scope. No this isn’t a full-fledged scope to which you can bind attributes like the other four—page, request, session, and application. Tag scope simply means that the variable was declared INSIDE a loop.

And you already know what that means in Java terms. You’ll see that for most other tags, a variable set with a “var” attribute will be visible to whatever scope you specifically set (using an optional “scope” attribute), OR, the variable will default to page scope.

So don’t be fooled by code that tries to use the variable somewhere BELOW the end of the <c:forEach> body tag!

It might help to think of tag scope as being just like block scope in plain old Java code. An example is the for loop you all know and love:

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You can even nest <c:forEach> tags

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You can even nest <c:forEach> tags