Check field values against a preset object

Question

I want to check some fields values in a form against an existing object's values. If the values match, change a class value (it will add a sign). The following code is working, but I would like to know if it can be improved.

Preset obj:

var obj = {
    preset_a:{
        input:{
            field_a:"value",
            ...
            field_b:"value",
        },
        select:{
            ...
        },
        radio:{
            ...
        }
    },
    preset_b:{
        input:{
            field_a:"value",
            ...
            field_b:"value",
        },
        select:{
            ...
        },
        radio:{
            ...
        }
    }
};

The script:

$(document).ready(function(){   
    for (var preset in obj){
        $.each(obj[preset], function(type){
            var flag = true;
            $.each(obj[preset][type], function(k, v){ 
                if (type == 'radio'){
                    flag = ((v) == $('#'  + k + ' > input[type="radio"]:checked').val());
                } else {
                    flag = ((v) == $(type + '#' + k).val());
                }  
                if (flag == false){   
                    return false;
                }   
            });
            if (flag == false){
                $(preset + ' i#id').attr('class', 'radio-unchecked');
                return false;
            } else {
                $(preset + ' i#id').attr('class', 'radio-checked on');
            }
        });
    }
});

Answer 1

Inside one of the $.each calls, you could simplify this part:

if (flag == false){   
    return false;
}

to this:

return flag;

When the value is true, $.each will continue normally, and stop after it is false, so the behavior remains the same.

---

Instead of:

if (flag == false) {

It's more common to write:

if (! flag) {

For simplicity, it might be a good idea to flip the condition:

if (flag) {
    $(preset + ' i#id').attr('class', 'radio-checked on');
} else {
    $(preset + ' i#id').attr('class', 'radio-unchecked');
    return false;
}

And to reduce code duplication, I would extract the dom lookup that is common in both branches of the if-else:

var preset = $(preset + ' i#id');
if (flag) {
    preset.attr('class', 'radio-checked on');
} else {
    preset.attr('class', 'radio-unchecked');
    return false;
}

---

The two innermost loops use $.each, but the outer loop is a traditional for. For the sake of consistency, it might be good to use $.each for all.