JSP | Expression tag

The Expression Tag in JSP is used to display output directly on the client’s browser. It allows embedding Java expressions inside a JSP page and automatically converts them into string output. This tag simplifies printing data without writing explicit output statements.

• Uses <%= %> syntax to write Java expressions
• Automatically prints output to the browser (no need for out.print())
• Mainly used for displaying data, not for writing logic

Syntax:

<%= expression %>

Difference from Scriptlet Tag

• Scriptlet (<% %>) → used for writing Java logic (loops, conditions)
• Expression (<%= %>) → used for displaying output
• Expression tag automatically converts into out.print()

Example

Explanation: In this example, the string "Welcome to GeeksforGeeks" will be printed directly in the client's browser.

Output

Implementation of JSP Expression Tag

Step 1: Create Dynamic Web Project

• Go to File -> New -> Dynamic Web Project
• Project Name: Geeks
• Select Apache Tomcat
• Click Finish

Step 2: Create index.html.

This HTML file takes the username from the user and sends it to Geeks.jsp on form submission

Output:

Step 3: Create JSP File

Here we are creating a jsp file names as Geeks.jsp

Explanation:

• <%@ page ... %>: Sets page settings (Java language, UTF-8 encoding).
• request.getParameter("username"): Retrieves the username entered in the HTML form.
• <% ... %>: Used for writing Java code (e.g., storing the username in a variable).
• <%= name %>: Outputs the value of name to the browser (auto-converted to out.print()).

If user enters Geeks, it displays: Hello Geeks!

Output: