即使条件不满足字符，JavaScript函数中的字符仍会重现false

Question

I am trying to learn JavaScript... I have function like, I take the format user id field... which is an email address and try to check if it matches below condition. However even thought I give the user name >3 and domain as gmail.com, I still get false return...Can someone please check and let me know why it is going into the if loop, do I have to trim the text or something.

Also if you can tell me how to write this effectively using jQuery that would help me learn. But if you think I am mixing two thing here... My priority is first question above.

function isValidate(eltt) {

    var flag      = true;
    var upos      = eltt.indexOf("@");
    var uendpos   = eltt.indexOf(".com");
    var totlength = eltt.length;
    var domain    = eltt.slice(upos,totlength);


    if ( upos < 3 | domain!="gmail.com" | uendpos=== -1) {
        flag=false;
    }

    return flag;
}

Answer 1

First, the problem is that you're using | instead of || . (The | is a bitwise or, which in this case will yield a basically random result by combining the bits of the binary representation of your conditions. Chances are, you'll never need | ; so use || and forget that | even does anything by itself.)

Second, this validation would be easier with a regular expression:

if (!eltt.match(/^.{3,}@gmail\.com$/)) {
  return false;
}

That is, it must start with ( ^ ) at least three characters .{3,} , followed by the literal text @gmail.com , with nothing after it ( $ ).