How to get session value in Javascript but my javascript code is in the code behind in asp.net. I am trying to set the variable value in javascript

Question

I am trying get the session value in javascript in my asp.net code behind. But the syntax is wrong I don't know how to get the session value. Here in my question i trying to set the value of sesindex variable which is a session value which i dont know how to set its totaly different

I tried to call javascript on page load normally its calling is fine. But when I am trying to set the variable value as session value its not calling alert box so their some where I put wrong but I don't know what it is.

Here is the code behind code:

str += "<script type='text/javascript'>" +
             //"alert('testing');" +
            "var sesindex = '<%=Session["indexval"]%>';" +
                "alert(sesindex);" +

                 "</script>";

I want to set sesindex value and show in alert box. I am trying to set the value but its not working. It is working fine in html page. But its not working in code behind.

Answer 1

Don't really like this but you can try this to get value into the string.

var sesVal = Session[indexval];

str += "<script type='text/javascript'>" +
        $"var sesindex = '{sesVal==null?"":sesVal.ToString()}'" +
            "alert(sesindex);" +"</script>";

This will get you covered when the value is null. You can read about $"{}" here .