trim last character from string?

I did:

phValue = phValue.substring(0, phValue.length - 1);

That code removes the last character as expected.

In my previous forum post I explained that I attempted to catch the \r by doing:

if (e.data != "\r" || e.data != "\n") {
      console.log("NO CR");
      phValue+=e.data;
    }

However, "NO CR" is echoing out 5 times instead of only 4. I have no idea why \r is getting stored to the phValue when the if statement I think should of filtered \r out. Can anyone explain why this is happening?