How to pass a jquery object to function?

Question

I am trying to write a generic code

var rodd = $('#checkBox');

I want to pass rodd to a function and check if it is checked

Callme(rodd);

$(rodd).click(function() {
Callme(this);
});

function Callme(rodd){
if(this.checked){
// do some behavior
}
}

Answer 1

If rodd is a jQuery object:

function Callme(rodd) {
  if (rodd.is(":checked")) {
    // ...
  }
}

or:

function Callme(rodd) {
  if (rodd[0].checked) {
    // ...
  }
}

Answer 2

Looking at your code, your passing in a jQuery object, rodd, into a function to return a jQuery object $(rodd).click...

It might be easier to do

$('#checkBox').click(Callme);

function Callme(rodd){

    if(this.checked){
    // do some behavior
    }

}

or

$('#checkBox').click(Callme);

function Callme(rodd){

    if($(this).is(':checked')){
    // do some behavior
    }

}

this also does away with the anonymous function event handler that is only executing Callme() passing in the event target. Working Demo here.

EDIT:

Currently, Callme(rodd) above expects a HTMLElement object to be passed in. If you want to be able to pass in a jQuery object, simply change to this

$('#checkBox').click(function(event) {

Callme($(event.target));

});

function Callme(rodd){

    if(rodd.is(':checked')){
     alert('checked');
    }

}

although personally, I would keep it as an element to be passed in and do the wrapping in the Callme function. you might want to consider prefixing the rodd parameter with $ to make it obvious that a jQuery object is expected.

Answer 3

This should work:

//Assuming rodd is a jquery element
Callme(rodd);

rodd.click(function() {
  Callme($(this));
});

function Callme(rodd){
  if(this.is(":checked"){
    // do some behavior
  }
}

remember that the event listener has this pointing at the DOM element, not the jquery element. Therefore you need to convert this into a jquery element, using the $(this) expression.