How to check if a key exists in an object in javascript

I have the following object literal:

{ 
  'key1': 
  { 
    id: 'rr323',

    d: undefined,
    x: 560,
    y: 150 
  },
  'key2': 
  { 
    id: 'rr231',
    d: undefined,
    x: 860,
    y: 90 

  } 
}

I want to implement an if statement such as below:

if(key DOES NOT exist in object){  
//perform certain function 
}

I tried the following:

var key = key1;
if(!(key in global_move_obj)){
 // function
}

But that always returns true value when it should return false.

Answer

Use the hasOwnProperty call

if (!obj.hasOwnProperty(key)) {

}

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwnProperty