The JSTL fn:replace() function or method in JSP (Java Server Pages) is mainly used for the manipulation of strings. This function allows developers to replace the occurrence of a specified substring with another substring in the given input string. This article will see the Syntax, parameters, and two practical examples of the fn:replace() function. We need to note that the replace function performs case-sensitive processing of string.

Syntax of fn:replace()

${fn:replace(sourceString, targetSubstring, replacementSubstring)}

Where,

• sourceString: This is the input or original string in which the replacement or modification is to be done.
• targetSubstring: This is the substring to be replaced in the sourceString.
• replacementSubstring: This is the substring that will mainly replace occurrences in the targetSubstring in the sourceString.

Example of fn:replace() function

Below is the implementation of the fn:replace() function:

Output:

Original String: GeeksforGeeks is a platform for computer science students. GeeksforGeeks is good.
Modified String: GFG is a platform for computer science students. GFG is good.

Final Output Shown in the Browser:

Explanation of the above Program:

• In the above example, we have initialised the “originalString” variable with the text.
• Then, we used the “fn:replace()” function to replace the occurrences of “GeeksforGeeks” with the “GFG” in the originalString variable.
• The replaced string is been saved in the “modifiedString” variable and we are printing it on screen using <p> tag in HTML.