find a value inside array of JSON object [closed]

Answer 1

For such array/collection manipulation in Javascript I would suggest you to use underscorejs library. It provides functions that, to me, make everything much more simple. In your case:

function find_value(array, key) {
    // find will run the provided function for every object in array
    var obj_found = _.find(array, function(obj) {
        // keys returns the keys inside an object
        // so if the key of currently examined object 
        // is what we are looking for, return the obj
        if (_.keys(obj)[0] === key) {
            return obj;
        }
   });
   // if an object with such key was found return its value
   if (obj_found) {
      return obj_found[key];
   } else {
      return null;
   }
}

Here is a working fiddle of what I am suggesting.