i saw some similar post at Stack, but i want to ask for specific function in jquery that is
$.urlParam('GETparameter')
Why simple
if($.urlParam('GETparameter') === undefined)
not working? And why there are complex answers at other questions?
Thank you for answers
Another solution here is the URLSearchParams function.
As an example, if your URL was https://example.com?foo=bar&baz=qux you could retrieve all of the parameters and then query the specific one like this:
var urlParams = new URLSearchParams(window.location.search); //get all parameters
var foo = urlParams.get('foo'); //extract the foo parameter - this will return NULL if foo isn't a parameter
if(foo) { //check if foo parameter is set to anything
alert('FOO EXISTS');
}
if(foo == 'bar') { //check if foo parameter is 'bar'
alert('FOO == BAR');
}
This is an overdue update, but as Frits's solution notes, using URLSearchParams is now the best approach.
const getQueryParameter = (param) => new URLSearchParams(document.location.search.substring(1)).get(param);
First off, $.urlParam is not an inherent jQuery function as far as I can tell, meaning you'll need to define it if you plan on using it.
When looking it up, I found a user-created function of the same name; I am going to assume that this is what you're referring to:
$.urlParam = function(name){
var results = new RegExp('[\?&]' + name + '=([^&#]*)').exec(window.location.href);
return results[1] || 0;
}
It looks like this will return 0 if the parameter is not found, rather than undefined. If this function is in fact the one you're referencing, you'll want to do this instead:
if($.urlParam('GETparameter') === 0)
$.urlParam = function(name){ var results = new RegExp('[\?&]' + name + '=([^&#]*)').exec(window.location.href); if (results === null) { return 0; } return results[1]; }If you want to check type of variable, you need to use something like:
if (typeof($.urlParam('GETparameter')) === 'undefined') {
..
}
=== undefined? See 2ality.com/2013/04/check-undefined.html
You could try this:
var url_param = $(location).attr('href').split("?");
var param = (url_param[1]);
Where url_param[1] is your second element in array (in this case your url parameters, if existing).
Then you can check with if(param!='') { // do something }
