Mixing Scriptlets and HTML

Suppose you have to generate a table in HTML.  This is a common operation, and you may want to generate a table from a SQL table, or from the lines of a file.  But to keep our example simple, we will generate a table containing the numbers from 1 to N.  Not very useful, but it will show you the technique.

Here is the JSP fragment to do it:

<TABLE BORDER=2>
<%
    for ( int i = 0; i < n; i++ ) {
        %>
        <TR>
        <TD>Number</TD>
        <TD><%= i+1 %></TD>
        </TR>
        <%
    }
%>
</TABLE>

The important things to notice are how the %> and <% characters appear in the middle of the "for" loop, to let you drop back into HTML and then to come back to the scriptlet.

The concepts are simple here -- as you can see, you can drop out of the scriptlets, write normal HTML, and get back into the scriptlet.  Any control expressions such as a "while" or a "for" loop or an "if" expression will control the HTML also.  If the HTML is inside a loop, it will be emitted once for each iteration of the loop.

Another example of mixing scriptlets and HTML is shown below -- here it is assumed that there is a boolean variable named "hello" available.  If you set it to true, you will see one output, if you set it to false, you will see another output.

<%
    if ( hello ) {
        %>
        <P>Hello, world
        <%
    } else {
        %>
        <P>Goodbye, world
        <%
    }
%>