push only unique elements in an array

Question

I have array object(x) that stores json (key,value) objects. I need to make sure that x only takes json object with unique key. Below, example \'id\' is the key, so i don\'t

Answer 1

This is late but I did something like the following:

let MyArray = [];
MyArray._PushAndRejectDuplicate = function(el) {
    if (this.indexOf(el) == -1) this.push(el)
    else return;
} 

MyArray._PushAndRejectDuplicate(1); // [1]
MyArray._PushAndRejectDuplicate(2); // [1,2]
MyArray._PushAndRejectDuplicate(1); // [1,2]