22 September 2005

Software: Simple Javascript Regular Expression Search and Replace

Here's a simple regular expression search and replace in Javascript (for JScript, replace alert with WScript.Echo). I wrote it as a test for another script to modify a configuration file.

var s1 = "Hello World"
var s2 = s1.replace(/Hello/, "Goodbye")
alert(s1 + "," + s2)
var s3 = s1.replace(/(Hello)/, "$1 Googly")
alert(s1 + "," + s3)

If you run this script in a Web page, you should see the first alert dialog containing "Hello World,Goodbye World" and a second alert dialog containing "Hello World,Hello Googly World".

In this example, the parentheses (()) enclose a match pattern and the dollar ($) symbol represents the matched string (i.e. $1 is the first matched string, $2 is the second matched string, etc.).