javascript - 检查jQuery中是否存在元素[重复](Check if element exists in jQuery [duplicate])

Question

This question already has an answer here:

(这个问题已经在这里有了答案：)

• Is there an “exists” function for jQuery?

  (jQuery是否有“存在”功能？)

  41 answers

  (41个答案)

How do I check if an element exists if the element is created by .append() method?

(如果该元素是由.append()方法创建的，该如何检查该元素是否存在？)

$('elemId').length doesn't work for me.

($('elemId').length对我不起作用。)

  ask by Nick translate from so

Answer 1

$('elemId').length doesn't work for me.

($('elemId').length对我不起作用。)

You need to put # before element id:

(您需要将#放在元素ID之前：)

$('#elemId').length
---^

---

With vanilla JavaScript, you don't need the hash ( # ) eg document.getElementById('id_here') , however when using jQuery, you do need to put hash to target elements based on id just like CSS.

(使用香草JavaScript时，您不需要哈希（ # ），例如document.getElementById('id_here') ，但是在使用jQuery时，您确实需要像CSS一样基于id将哈希放入目标元素。)