javascript - Check if key / value pair exist within another object -

if have following 2 objects (object , object b), how can check if object b's key/value exists object a? in below example should return true because both 'make: "apple"' , 'model: "ipad"' exists in object a.

edit: object b dynamic , may contain make or model. more keys added dynamically via checkbox filters.

is easier use library such underscore? if functions applicable?

i hope makes sense?

        var = {             make: "apple",             model: "ipad",             hasscreen: "yes",             review: "great product!",         }          var b = {             make: "apple",             model: "ipad"         } 

just iterate on keys , check if values equal.

var = { make: "apple", model: "ipad", hasscreen: "yes", review: "great product!" },      b = { make: "apple", model: "ipad" },      every = object.keys(b).every(function (k) {          return a[k] === b[k];      });    document.write(every);