check if input is checked using jquery

Question

How would I achieve this:

if($(this).parent().find('input:checked') == true)

{$(this).find('.switch').attr('state','on');}
else{$(this).find('.switch').attr('state','off');}

I know this is wrong but you get the idea I think :). If there is an input that is checked add state on if not state off.

Answer 1

Try with

if($(this).parent().find('input').is(':checked')) {
    something();
}

This works if there's only one checkbox.

Answer 2

It is not necessarily wrong, but the selector returns all elements that apply to the condition. Therefore you have to check if the length is not 0:

if($(this).parent().find('input:checked').length)

Answer 3

Supposign input[type=checkbox] = this, you can check it on the element itself.

Source: jQuery docs

$("input[type=checkbox]").change(function(){
    if ( this.checked ){}
    //or
    if ( $(this).prop("checked") ){}   
    //or
    if ( $(this).is(":checked") ){}
});

Answer 4

This also works if you know the id of the input html element:

if($('input#element_id_name:checked').length>0) {
  //your code here.
}