jquery - form validate rules required depends

Question

Can somebody give me a primer on how to use the validate, rules, required, depends. I have some partial code but not sure

Answer 1

$("#form2").validate({
rules: {
    firstname: {     //This rule applies to the $('#form2 input[name="firstname"]') selector

        required: {  //This can be a true/false boolean, string, or a complex field using depends.

            depends: function () { //depends takes a function pointer that
                                   //returns a value, informing the rule 
                                   //if it is required. In this case, always true.

                $(this).val($.trim($(this).val()));

                return true;
            }
        },

        minlength: 2 // the minimum length of text in the field is 2 characters.
    },