Javascript String Compare == sometimes fails

Question

How could the following code sometimes evaluate to false?

(transport.responseText == \'1\' || 
 transport.responseText == \'CARD_VALID\')

M

Answer 1

Try capturing the value of responseText into a different variable before entering that code block, in case the variable is updated somewhere in there.

I don't have that much experience directly using XmlHttpRequest, but I do know that javascript has a number of places where it uses volatile references to interface objects that can change during execution, rather than a simple value.