Perhaps those two lines are the same in JS and PHP (I do not have PHP installed so I can't confirm, but I do have node installed):

    > 9223372036854775807 == 9223372036854775808
    true
    > 9223372036854775807 === 9223372036854775808
    true

However, that is not the two lines written about in this post. The following works as one would expect on JS, but (I assume, based on the report) not in PHP:

    > "9223372036854775807" == "9223372036854775808"
    false
    > "9223372036854775807" === "9223372036854775808"
    false

The difference being that the php code sample is trying to compare two strings.

While this comment is beside the point, I'm still curious why this version works the way it does. I may be missing something obvious, but why does JS think those two integers are the same?

JavaScript doesn't have an fixed integer data type.

Is "javascript does it too" supposed to be a defence?