var student = {             "name" : "Guo",             "sex" : "",             "age" : "",             "num ": 01,             "scores" : [                     {                         "subject" : "English",                         "score" : 50,                         "comment" : ""                     },                     {                         "subject" : "Computer",                         "score" : "",                         "comment" : "absent"                     }                 ]         };         var exclude = ["sex", "comment"];         // method 1 to validate obj         validateObj1 = function(obj, excluded){             var value;             for(var key in obj){                 value = obj[key];                 if($.isArray(value)){                     obj = validateArray1(obj, key, excluded);                 }else if(($.inArray(key, excluded) == -1) && ($.isBlank(value))){                     obj[key] = "N/A";                 }             }             return obj;         }         validateArray1 = function(obj, key, excluded){             var subValue;             for(var i = 0, length = obj[key].length; i < length; i++){                 for(var subKey in obj[key][i]){                     subValue = obj[key][i][subKey];                     if(($.inArray(subKey, excluded) == -1) && ($.isBlank(subValue))){                         obj[key][i][subKey] = "N/A";                     }                 }             }             return obj;         }         // method 2 to validate obj         validateObj2 = function(obj, excluded){             $.each(obj ,function(key, value){                 if($.isArray(value)){                     obj = validateArray2(obj, key, excluded);                 }else if(isInvalid(key, value, excluded)){                     obj[key] = "N/A";                 }             });             return obj;         }         validateArray2 = function(obj, key, excluded){             for(var i = 0, length = obj[key].length; i < length; i++){                 $.each(obj[key][i] ,function(subKey, subValue){                     if(isInvalid(subKey, subValue, excluded)){                         obj[key][i][subKey] = "N/A";                     }                 });             }             return obj;         }         isInvalid = function(key, value, excluded){             return (($.inArray(key, excluded) == -1) && ($.isBlank(value))) ? true : false;         }         $.isBlank = function(obj){             return(!obj || $.trim(obj) === "");         };