链接双等于==返回false

Question

I have 3 textboxes that I am trying to do some validation that all 3 values match. I have a simple function:

    function DoesSubsriberSignatureMatch() {
    return tbNameOfSubscriber.GetText() == tbSubscriberSig1.GetText() == tbSubscriberReEnter.GetText();
}

I stepped through with the debugger, and it seems in Javascript in Chrome at least, "a"=="a" returns true, but "a"=="a"=="a" returns false.

Why?

Answer 1

Coming from Python, perhaps? Most languages don't actually have comparison chaining. Trying it produces nonsense results.

Answer 2

Because a == a yields true , and true != a .

(Unless a holds the value true ).

Answer 3

Take

"a"=="a"=="a"

and break it down. So first

"a" == "a"

equals what? true . Right. Now substitute true in for that first part

true == "a"

which of course is false