Uncaught syntax error: invalid regular expression flags ( see page source code )

1. Summary

JS or jQuery errors look at the page source code, and all of a sudden the errors are very clear JS or jQuery errors

2. Uncaught syntax error: invalid regular expression flags

This error occurs when the page uses Ajax in jQuery

1 $(document).ready(function(){
2   $("#b01").click(function(){
3   htmlobj=$.ajax({url:"/jquery/test1.txt",async:false});
4   $("#myDiv").html(htmlobj.responseText);
5   });
6 });

The answer to the Internet is:

@Url.Actiononly returns the action url’s string, without quotes around it.

You’ll need to wrap that url in quotes.

Replace:

url: @Url.Action("ReturnMethodTest", "HomeController"),

With:

url: '@Url.Action("ReturnMethodTest", "HomeController")', // ^ ^

Otherwise, the file returned to the client will contain:

url: /HomeController/ReturnMethodTest,

Which isn’t valid JS, nor what you want. The replacement gives the following result:

url: '/HomeController/ReturnMethodTest',

Which is a perfectly valid JavaScript string.

look at the static HTML converted from the dynamic HTML of the next page (commonly known as the page source code): it’s easy to find the error