jQuery implements the case-insensitive method of containing method

This article describes the case-insensitive method of jQuery implementing the contains method. Share it for your reference. The specific implementation method is as follows:

// NEW selector  
[':'].Contains = function(a, i, m){
 return jQuery(a).text().toUpperCase()
   .indexOf(m[3].toUpperCase()) >= 0;
};  
 
// OVERWRITES old selecor
[':'].contains = function(a, i, m){
 return jQuery(a).text().toUpperCase()
   .indexOf(m[3].toUpperCase()) >= 0;
};

usage:

$("div:contains('John')")

Test HTML files:

<div>john</div>
<div>John</div>
<div>hey hey JOHN hey hey</div>

I hope this article will be helpful to everyone's jQuery programming.