Assigning Java variable value to Javascript variable

Question

How to assign a java variable vale to an javascript varible. I have tried the following scripting elements:

<%
double x=23.35;
%>
var temp='<%= x %>';
var temp="<%= x %>";
var temp='${x}';

they returned an output as follows:

<%= x %>
<%= x %>
${x}

You might want to try this - [JSP: EL expression is not evaluated](http://stackoverflow.com/q/793983/738746). — Bhesh Gurung, Apr 20 '14 at 17:19
I tried your suggestion Bhesh but no change in my output. Actually I am not working on an web application, but calling this jsp file from a java code. I am working on SWT browser for uploading google maps — Shashank Bhagat, Apr 20 '14 at 17:31
Is this in a JSP or in a JS file? Also, have you considered making an AJAX call and returning JSON? — Elliott Frisch, Apr 20 '14 at 17:32
It's probably because your java call is in quotations. Try `var temp = <%= x %>`. If this is a JSP file, the value should be replaced before the JavaScript interpreter gets to it. — rescuecreative, Apr 20 '14 at 17:43
var temp = <%= x %> would not load my google map. it seems that it is not accepting value through that scripting style — Shashank Bhagat, Apr 20 '14 at 17:48
@ShashankBhagat: 'I am working on SWT browser' - does this mean your application is a desktop application, rather than a web application? In that case, why are you using JSPs? — Luke Woodward, Apr 20 '14 at 19:19

score 1 · Answer 1 · answered Apr 20 '14 at 18:19

1

Try this-it should work. (No '=' needed inside java code).

var temp=<% x %>;
var temp=<% x %>;
var temp=${x};

answered Apr 20 '14 at 18:19

kellzer

131
1
3
18

without the '=' sign it gives an error. And ${x} does not load my google map means it is not accepting that value. – Shashank Bhagat Apr 20 '14 at 18:32

score 0 · Answer 2 · answered Mar 09 '21 at 10:32

You have tried three ways. I have tried in JSP inside the script tag and below work for me fine except for the third way.

 <% double x = 23.35; %>
    
 var temp = <%=x%>;
 console.log(temp);
 console.log(typeof(temp));

 var temp2 = '<%=x%>';
 console.log(temp2);
 console.log(typeof(temp2));

 var temp3 = "<%=x%>";
 console.log(temp3);
 console.log(typeof(temp3));

The difference is if we assign value to a variable within single quotes or double quotes, it treated as a string otherwise number. If you assign value as <c:set name="x" value="23.35" /> then can access by '${x}'.

Assigning Java variable value to Javascript variable

2 Answers2