Test whether an element exists
4521
Is there an "exists" function for jQuery?
133200
Test if a vector contains a given element
64643
Pythonic way of checking if a condition holds for any element of a list
134025
How to check if an array value exists?
80984
How do I check if an HTML element is empty using jQuery?
91447
Check if a method exists
40229
How do I check if a variable exists?
6288
How do I check if an object has a specific property in JavaScript?
64809
How to check if a folder exists?
155520
Why does $('#id') return true if id doesn't exist?
38053
php check if file exist
50331
jQuery how to find an element based on a data-attribute value?
121066
How to check if list item already exist when adding it with
96267
How to check if post has any tag?
22337
How to test if a list contains another list?
74576
How to know if an object has an attribute in Python
43713
How can I test if two jQuery wrapped DOM elements are the same?