Expression tag is used to insert Java values directly into the output.
Syntax for the Expression tag is: <%= expression %>
An expression tag contains a scripting language expression that is evaluated, converted to a String, and inserted where the expression appears in the JSP file. The most commonly used language is regular Java.
In Advanced Java, specifically in the context of JavaServer Pages (JSP), an expression refers to a scripting element used to insert dynamic content into the HTML code generated by the JSP page. Expressions are enclosed within <%= %> tags and are evaluated, converted to a string, and then inserted into the output HTML during the page’s execution.
For example:
<p>Current Date and Time: <%= new java.util.Date() %></p>
In this example, the expression <%= new java.util.Date() %> will be replaced with the current date and time when the JSP page is executed, and the result will be included in the HTML output.
It’s important to note that expressions are limited to evaluating and outputting data, and they are not meant for control flow or complex logic. They are primarily used for embedding dynamic data within the HTML markup of a JSP page.