How to efficiently check if a Key Value pair exists in a Javascript "dictionary" object

Question

Given:

        var dic = {1: 11, 2: 22}

How to test if (1, 11) exists?

Answer 1

If you need to check both if the key exists, and has a value, the below piece of code would work best:

function hasKeySetTo(obj,key,value)
{
    return obj.hasOwnProperty(key) && obj[key]==value;
}

It only returns true if obj has a key called key and that key has value as its value.