$(...).length is not a function in jQuery

JavaScript
1 
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
    <script>
    function count(){
        alert("There are " + $("p").length() + " paragraphs.");
    }
</script>
</head>
<body>
    <p>This is first para</p>
    <p>This is second para</p>
    <p>This is third para</p>
    <p>This is fourth para</p>

<form>
    <input type="button" value="Count Paragraphs" onclick="count()"></input>
</form>

</body>
</html>

ERROR
Uncaught TypeError: $(…).length is not a function
at count (index.html:11)
at HTMLInputElement.onclick (index.html:22)

2

I think you’re looking for $("selector").size(). Length is JavaScripts native property. Gotta love abstractions (just kidding)

3

Also, length is not a function :slight_smile:

According to the .size() doc page, using length is the preferred solution.

5

So what is the correction in that code?

alert(“There are " + $(“p”).length() + " paragraphs.”);

6

Look at the documentation.
length is not a function, it’s a property.

7

Also if my memory doesn’t fail you cannot use length off a jQuery object ?

8

Ahh yes - the answer is to just remove the function invoking parenthesies.

9

Yes you can, that is now the preferred way of getting the number of matched elements.
https://api.jquery.com/length/

1 Like
10

In case the above comments weren’t explicit enough, you just need to remove the () from .length():

alert("There are " + $("p").length + " paragraphs.");
3 Likes
11

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