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

Double equals is the appropriate way to compare strings in Javascript, it is returning false then there may be whitespace to the left and or right of one string.

Put a .trim() on the end of the strings and my comparison should started working:

var panel = response.substr(0, response.indexOf("<")).trim();
if(panel == "combo"){
    //do something
}