How to get the parameter value or key value on the the window location (page URL)?

How to get the parameter value or key value on the the window location (page URL)? If you have this URL “examplesite.com/?debug=1” and thinking how to get the value of debug parameter, the codes below is the answer.

jQuery( document ).ready( function($){
// Example URL is examplesite.com/?debug=1
var getPostValue = function getPostValue(key) {
    var pageURL = decodeURIComponent(window.location.search.substring(1)),
        URLvar = pageURL.split('&'),
        keyName,
        i;

    for (i = 0; i < URLvar.length; i++) {
        keyName = URLvar[i].split('=');

        if (keyName[0] === key) {
            return keyName[1] === undefined ? true : keyName[1];
        }
    }
};
if( getPostValue( 'debug' ) ){
// your codes
}
});