Javascript code inside var

Question

I need to add some HTML and Javascript code inside a javascript variable to write them later in my .html page

example of what i tried to write in my Javascript page

var footer = "<footer><script>
if(isMobile.any()){
document.write('<a href="twitter:///user?screen_name=twitter">');
} else {
    document.write('<a href="https://twitter.com/twitter">');
}</script></footer>";

and the way im writing it in my HTML document

<script>document.write(footer);</script>

but im getting errors inside my javascript page caused by the javascript code inside the variable

sorry i'm new in javascript and thanks in advance

@putvande in the real world of 3'rd parties js- you almost always use it — Royi Namir, Mar 11 '14 at 12:07
@laaposto dreamweaver saying that "there is a syntax error on line 8. code hinting may not work until you fix it" — Fouad, Mar 11 '14 at 12:10

score 3 · Accepted Answer · answered Mar 11 '14 at 12:11

Strings can't go across multiple lines without proper handling; embedded quotes need to be escaped too; this is by no means the cleanest way, but one suggestion could be:

var footer = 
  "<footer><script>" +
    "if(isMobile.any()) {" +
      "document.write('<a href=\"twitter:///user?screen_name=twitter\">');" +
    "} else {" +
      "document.write('<a href=\"https://twitter.com/twitter\">');" +
  "}" +
  "</script></footer>";

Also note that you use document.write inside script tags, when your literal script string has that tag. You need it for that piece of script, but you might consider your overall output.

score 2 · Answer 2 · answered Mar 11 '14 at 12:10

You need to escape the quotes(") inside the string like \":

var footer = "<footer><script>
if(isMobile.any()){
document.write('<a href=\"twitter:///user?screen_name=twitter\">');
} else {
    document.write('<a href=\"https://twitter.com/twitter\">');
}</script></footer>";

score 1 · Answer 3 · answered Mar 11 '14 at 12:13

1

var footer = "<footer><script>
if(isMobile.any()){
document.write('<a href='twitter:///user?screen_name=twitter'>');
} else {
document.write('<a href='https://twitter.com/twitter'>');
}</script></footer>";

as another answer already pointed out, when the second double qute is encountered, it's considered as the end if the string, you've to either escape it, or use single quotes throughout the string, as above.

answered Mar 11 '14 at 12:13

T J

42,762
13
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you need to escape newlines, otherwise you will get `SyntaxError: Unexpected token ILLEGAL` when running your code – anurupr Mar 11 '14 at 12:34

score 1 · Answer 4 · edited May 23 '17 at 10:33

1

This is a slight modification to @Grant Thomas's answer

var footer = "<footer>\x3Cscript>\
   if(isMobile.any()){\
     document.write('<a href=\"twitter:///user?screen_name=twitter\">');\
   } else {\
    document.write('<a href=\"https://twitter.com/twitter\">');\
   }\x3C/script></footer>";

You can read up about why you need to use \x3c here Link

edited May 23 '17 at 10:33

Community

1
1

answered Mar 11 '14 at 12:14

anurupr

2,294
2
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Javascript code inside var

4 Answers4