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

I had the same problem and i noticed that i was comparing two objects

to solve this issue i had to use

JSON.stringify(user._id) === JSON.stringify(userId) // true 

Answer 2

If you want something a little less complicated and you are dealing with NUMERIC VALUES, use

parseFloat()

works like a charm

Answer 3

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
}