javascript - Using indexOf( ) to check if particular object exists in JS Array -

this structure of array:

[{"stockcode":"pallet cards","quantity":"2"},  {"stockcode":"pallet cards","quantity":"3"},  {"stockcode":"cbl202659/a","quantity":"1"},  {"stockcode":"cbl201764","quantity":"3"}]  

when order button clicked check if stockcode exists in array. each time -1 returned.

this code check stockcode:

$(".orderbtn").click(function(event){         //check ensure quantity > 0         if(quantity == 0){             console.log("quantity must greater 0")         }else{//it continue             //show order box             $(".order-alert").show();             event.preventdefault();              //get reference product clicked             var stockcode = $(this).closest('li').find('.stock_code').html();             //get reference quantity selected             var quantity = $(this).closest('li').find('.order_amount').val();              //order item (contains stockcode , quantity) - can add whatever data here             var orderitem = {             'stockcode' : stockcode,             'quantity'  : quantity             };              //check if cookie exists              if($.cookie('order_cookie') === undefined){              console.log("creating new cookie");             //add object array             productarray.push(orderitem);              }else{//already exists              console.log("updating cookie")             productarray = json.parse($.cookie('order_cookie'));              //check if item exists in cookie , update qty             if(productarray.indexof(stockcode)!= -1){                  //get original item , update                 console.log("updating existing entry " + productarray.indexof("pallet cards"));             }             else{                 console.log("adding new entry ");                 //insert item array                 //productarray.push(orderitem);             }             }         }          //update cookie         $.cookie('order_cookie', json.stringify(productarray), { expires: 1, path: '/' });          //testing output of cookie         console.log($.cookie('order_cookie'));     }); 

i reference stockcode when user clicks on order button:

        var stockcode = $(this).closest('li').find('.stock_code').html(); 

i check if stockcode in array , if not adding new entry, rather, updating existing one.

i hope i'm getting right:

   function findbystockcode(code, stockcodearr){            return stockcodearr.filter(function(elem){               return elem.stockcode == code;            });    } 

this ofcourse give array back. if length greater 0 element given code in array already. think filter-function has been added @ ecma5 ie8 won't support it.
[https://developer.mozilla.org/en-us/docs/web/javascript/reference/global_objects/array/filter][1] mentions fallback case filter not implemented in current browser.
anyway there's similiar jquery-function in 'this' refers actual element:

function jqueryfindbystockcode(code, stockcodearr){                return $(stockcodearr).filter(function(){                   return this.stockcode == code;                });        } 

edit:
dhruvpathak mentioned $.grep might more appropriate solution jquery's filter. (grep vs filter in jquery?)

looked again solution better performance (seems) have write on own (it's pretty simple anyway):

//for defined, non-null values function findfirstbyproperty(arr, prop, value){     for(var = 0 ; < arr.length; i++){          if(arr[i]!=null && "undefined" !== typeof arr[i] && arr[i][prop] == value)               return arr[i];     }     return null; } 

this should have better performance (especially big arrays). in average (assuming there's such element in array) should in average twice fast filter , grep (since stops @ first match).