Testing for Variable Existing

Francois Laberge

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Aug 3, 2011, 2:21:15 PM8/3/11

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Is it possible to test if a variable has been defined? For example if
I don't pass a 'title' variable into the template, can I detect that
and supply a default or different behavior?

The following code fails when no loginForwardUrl is passed in from my
Node.js app.

<% if(loginForwardUrl!=undefined) {%>
loginForwardUrl = "<%= loginForwardUrl %>";
<% } %>

I get this error
ReferenceError: /Users/francoislaberge/Sites/playbrassmonkey.com/views/
index.ejs:3
1| <html>
2| <head>
>> 3| <% if(title!=undefined) {%>
4| <title><%= title %> - Brass Monkey</title>
5| <% } else {%>
6| <title>Brass Monkey</title>

I banged my head agains this for too long. It seems so basic.

Thanks in advance,
Francois

Justin Meyer

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Aug 3, 2011, 2:33:59 PM8/3/11

to Embedded JavaScript

try if(this.loginForwardUrl)

Max Hwang

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Aug 3, 2011, 2:39:38 PM8/3/11

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Use the JS function typeof:

It'd be something like

If (typeof(loginForwrdUrl) != 'undefined') {
// blah blah
}

-Max

Thanks in advance,
Francois

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Francois Laberge

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Aug 3, 2011, 2:42:00 PM8/3/11

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Thanks! That worked.

try if(this.loginForwardUrl)

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Francois Laberge

Chief Innovation Officer

Brass Monkey Inc.

http://brassmonkeysdk.com/