JSON Object validation in JavaScript

if you wish to validate the object to a certain schema, you could try JSD Validator

Building on the idea of @Quentin, you can just do something like:

function isValidJson(json) {
    try {
        JSON.parse(json);
        return true;
    } catch (e) {
        return false;
    }
}

console.log(isValidJson("{}")); // true
console.log(isValidJson("abc")); // false

This will require json2.js to be deployed in the page in order to ensure cross-browser support for the JSON Object.