js function as string inside StringBuilder C#

I'm new in .net platform and I'm curious about how can I pass js function with curly brackets as string inside StringBuilder.AppendFormat() c#.here is what I'm willing to do

StringBuilder sb = new StringBuilder();

sb.AppendFormat(@"<script>
       var vm = new Vue({
        el: 'main_div',
        data() { 
            return {
                proddetails: [],
            }
        },
        created: function () {
            this.proddetails = { jsonobjectplaceholder };
        },
    });
</script>");

sorry for stupidity if any and thanks in advance for the attention!

expecting a reasonable answer

You are using AppendFormat where first parameter is Formatted string. And if you wish to use curly braces inside it then you need to escape them double braces {{ and }}. Try like below.

Referene : Escape curly brace '{' in String.Format

sb.AppendFormat(@"<script>
       var vm = new Vue({{
        el: 'main_div',
        data() {{ 
            return {{
                proddetails: [],
            }}
        }},
        created: function () {{
            this.proddetails = {{ jsonobjectplaceholder }};
        }},
    }});
</script>", "");

Alternatively you can use Append instead of AppendFormat. Try like below and it will work.

StringBuilder sb = new StringBuilder();

sb.Append(@"<script>
       var vm = new Vue({
        el: 'main_div',
        data() { 
            return {
                proddetails: [],
            }
        },
        created: function () {
            this.proddetails = { jsonobjectplaceholder };
        },
    });
</script>");

Your code contains 'AppendFormat', did you mean to use 'Append'?

'StringBuilder.AppendFormat' is used for creating a string that is formatted with an array of strings.

For instance:

sb.AppendFormat("{0}, {1}, {2}", "var1", "var2", "var3");

The above will result in: "var1, var2, var3"

See more about StringBuilder.AppendFormat here: See Here

You can use the '@' symbol as a verbatim identifier which will allow you to include multiple lines in your string.

See Here

string exampleString = $@"This
is a
string";

So the code you want looks like the following:

StringBuilder sb = new StringBuilder();
sb.Append(@"<script> var s = 'myStringValue'; </script>");