Recently I noticed that the DataContractJsonSerializer does something peculiar with the .NET Dictionary type when serialising it to JSON. I assumed, wrongly, that it would be converted to an associative array with the dictionary item key as the associative and the dictionary item value as object in the array. For example, the following dictionary in C#….

var myDictionary = new Dictionary<string, string>();
myDictionary.Add("key1", "Hello");
myDictionary.Add("Key2", "World");

..could be accessed (after JSON serialisation) in Javascript like this:

var myWorld = myJsonDictionary["key2"];

Unfortunately, this isn’t the case. When the Dictionary is serialised to JSON it is outputted as an array of key/value pair objects. So, you have to access the key and value like so:

var myKey = myJsonDictionary[1].Key;
var myValue = myJsonDictionary[1].Value;

As you can imagine, this makes it difficult to find the value for a particular key.

For a solution to this problem I came up with the following jQuery function to return the dictionary value:

GetDictionaryValue: function(array, key) {
        /// Get the dictionary value from the array at the specified key
        var keyValue = key;
        var result;
        jQuery.each(array, function() {
            if (this.Key == keyValue) {
                result = this.Value;
                return false;
        return result;

This function uses the jQuery.each function to go around the array and check if the key of the object within matches the passed in value. When it finds a match it assigns it to the result variable and returns false to exit the loop.

This function can then be used on any key/value pair arrays within jQuery, like so:

var myValue = MyDictionary.GetDictionaryValue("key2");