[рони]

Marson,

function map(object, callback){
for(var key in object)  Object.assign(object,callback(key, object[key])), delete object[key];
}
var object = {name: 'Ivan', age: 24};
map(object, function(key, value){
  var result = {};
  result[key+"_"] = value + "$";
  return result;
})
alert(JSON.stringify(object, null, 4));