如何在javascript正则表达式中包含变量？

Question

I have been searching an answer for like three days but still cannot find one that works. I have this if statement in javascript block:

if (!(/@test.com\s*$/.test(document.forms["myForm"]["email"].value))) {
          alert("Please Enter Correct Email Domain"); 
            return false;
        }

I need to have this: var javaScriptVar = "<?php echo $ar[1]; ?>"; to replace the test.com part in the if statement. Any idea how to do this? Thanks.

Answer 1

Use the RegExp constructor instead of a literal (note that you need to escape backslashes when taking this approach):

var regex = new RegExp("@" + someVar + "\\s*$");
//                                      ^--- Notice the escaped backslash