699645 - [Javascript] Wrong comparision (0.55*100 == 55) always return false

Status: RESOLVED DUPLICATE of bug 5856

(Firefox :: General, defect)

Description

[Nghia Do]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.202 Safari/535.1

Steps to reproduce:

In my code there is one compassion like
var x = 0.55
if (x*100 == 55) {
// do something
} 


Actual results:

There is no way to make the condition to true. 


Expected results:

0.55*100 == 55 should return true

Comment 1

[Masatoshi Kimura [:emk]]

Learn about floating point number calculation.

Comment 2

[Nghia Do]

Ok, my question is 
Why 0.33*100 returns 33 but 0.55*100 returns 55.00000000000001.