jquery - encountering error in this.replace

hey there all,

can you kindly see the below and assist me.

I am getting the below error while using the code below-

" TypeError: Result of expression 'this.replace' [undefined] is not a function."

Here’s the code-

 (function($){
 
$.fn.ToCode = function(){
return this.each(function(i){
var line = $(this).html().replace(/\n/g, "<li>").trim();
if (line.match("<li>") !== "<li>") tmp = "<li>" + line + "<\/li>";
$(this).html("<ol class=\"code\">" + tmp + "<\/ol>");
//$(".code li:nth-child(odd)").addClass("alt");
$(".code li:first-child, .code li:last-child").css("display","none");
});
};
})(jQuery);

It has been stated as a substitute for some Javascript that edits code blocks to lists.

Its not functioning on my platform-

This is how it is called-

$(document).ready(function () { 
 //Code
 $('code').ToCode();
 ...
});

Gives this error -

"TypeError: Result of expression '$('code').ToCode' [undefined] is not a function."

Can u find the missing point ???

Thanks!