How to add pseudo-elements to this in jquery?

Question

css

Here is the code (not added):

$('label').on('click', function(){
                if($(this).children('input').prop('checked')){
                    $(this)
                }
            });

It is necessary that when the inner input is checked, the outer label:befor change css

<label><input></label>

Answer 1

$('label').on('click', function(){
    if($(this).children('input').prop('checked')){
        $(this).addClass('checked');
    }
});

CSS:
label.checked:before {...}