Expression Language Basic Arithmetic
EL means the expression language , it makes it possible to easily access application data stored in JavaBeans components. The jsp expression language allows a page author to access a bean using simple syntax such as $(name). Before JSP 2.0, we could use only a scriptlet, JSP expression, or a custom tag to include server state in the jsp page output. Expression Language (EL) was first introduced in JSTL 1.0. EL makes it easier to integrate server side state with the presentation output.
EL expression is always written between the delimiters ${ and }. In the JSP page response, the result of expression evaluation replaces the expression and its delimiters in the template text. Within tags, expression can be used only in attribute values.
The basic Expression Language arithmetic are: Addition (+), subtraction (-), multiplication (*), division (/ or div), and modulus (% or mod) are all supported in Expression Language. Error conditions, like division by zero are handled easily by the expression language.
In this example we are just using the arithmetic expression for EL.
The code of the program is given below:
<html>
<head>
<title>Basic Arithmetic</title>
</head>
<body>
<h1>Basic Arithmetic</h1>
<hr>
In this example we are doing basic arthmetic.
Error conditions, like
division by zero, are handled gracefully.
<br>
<blockquote>
<code>
<table border="1">
<thead>
<td><b>EL Expression</b></td>
<td><b>Result</b></td>
</thead>
<tr>
<td>\${2}</td>
<td>${2}</td>
</tr>
<tr>
<td>\${2 + 2}</td>
<td>${2 + 2}</td>
</tr>
<tr>
<td>\${2.2 + 2.3}</td>
<td>${2.2 + 2.3}</td>
</tr>
<tr>
<td>\${2.2E4 + 2.4}</td>
<td>${2.2E4 + 2.4}</td>
</tr>
<tr>
<td>\${-2 - 2}</td>
<td>${-2 - 2}</td>
</tr>
<tr>
<td>\${2 * 2}</td>
<td>${2 * 2}</td>
</tr>
<tr>
<td>\${2/4}</td>
<td>${2/4}</td>
</tr>
<tr>
<td>\${2 div 4}</td>
<td>${2 div 4}</td>
</tr>
<tr>
<td>\${2/0}</td>
<td>${2/0}</td>
</tr>
<tr>
<td>\${12%4}</td>
<td>${12%4}</td>
</tr>
<tr>
<td>\${12 mod 4}</td>
<td>${12 mod 4}</td>
</tr>
<tr>
<td>\${(1==2) ? 3 : 4}</td>
<td>${(1==2) ? 3 : 4}</td>
</tr>
</table>
</code>
</blockquote>
</body>
</html>
|
The output of the program is given below:
