"'$' is undefined" alert message shows

Question

The following code always generates the $ is undefined alert message.

Here is the code for the Script tag:

function CheckString() {
  try {
    var s = "";
    s = $('#regExString').val();
    alert(s);
    var regExpression = /^[A-Z,a-z]\d[A-Z,a-z][\s{1}]?\d[A-Z,a-z]\d/;

    if (regExpression.test(s))
      alert("Valid postal code.");

    else
      alert("Invalid postal code.");

  } catch (e) {
    alert(e.message);
  }
}

The html input text tag is passed as the text field and a button has this function (CheckString) as its on click function which validates the regular expression

Where do you assign a value to *$*? It's not a built–in object. — RobG, Dec 28 '16 at 08:24

score 0 · Answer 1 · answered Dec 28 '16 at 08:23

0

This is because jQuery has not been imported into your web solution.

In your HTML file in between your head tags, add this:

<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
</head>

answered Dec 28 '16 at 08:23

nashcheez

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*$* is used by libraries other than jQuery. – RobG Dec 28 '16 at 08:24
Yes true, but the `val()` method here with an input box hints at jQuery being the library used here. – nashcheez Dec 28 '16 at 08:26

"'$' is undefined" alert message shows

1 Answers1