I'm learning JavaScript now and I've been told by the book I'm following that there's a “slight technical difference” between == and ===. What exactly is the difference? From my super basic number/variable comparisons using == and === they both seem to work exactly the same.

== tries to convert the values to the same type before comparing them, so
converts the text “0” to a number and returns true because both numbers are equal. This sometimes behaves weirdly:

The === operator doesn't do this, so comparing values of different types using it returns false. When both values have the same type, there is no difference.

adding on, use === if you want “strict equality”, for example:



it's useful to know this difference when dealing with user input within critical parts in your code.

Maximouse wrote:

== tries to convert the values to the same type before comparing them, so

0 == "0"

converts the text “0” to a number and returns true because both numbers are equal. This sometimes behaves weirdly:

"0" == 0 // true
[] == 0 // true
"0" == [] // false

The === operator doesn't do this, so comparing values of different types using it returns false. When both values have the same type, there is no difference.

Jeffalo wrote:

adding on, use === if you want “strict equality”, for example:



it's useful to know this difference when dealing with user input within critical parts in your code.

Ah, alright. I guess that's way more than a “slight” technical difference. Will be super helpful for the future, thank you for the replies.