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

A1 = "speed"
A2 = "speed" 

if(A1 == A2)  => Error !!!

USE THIS TEST IN CONSOLE:

escape("speed")

result: "speed"

escape(A1)

result: "speed%0D" => This is the problem %0D !!!

escape(A2)

result: "speed" => OK !!!

Use correct code:

if(A1.slice(0, -1) == A2) This is OK!