How to check if an object with an ID already exists on the page? [duplicate]

This question already has answers here: Closed 11 years ago.

Possibl开发者_Python百科e Duplicate:

Is there an “exists” function for jQuery

Say for instance you have the div:

<div id="hello"></div>

And you are dynamically creating a div:

<div id="hello"></div>

Is there a function you can use in Jquery which will check to see if the object with the ID you are trying to create already exists on the page?

---

For jQuery method you could go with

if($("#selector").length) {
    //object already exists
}

---

if (document.getElementById('hello')) {
    // yup, already there
}

Or, the jQuery way:

if ($('#hello').length) {
    // yup, already there
}