如何在javascript中检查对象中是否存在密钥

Question

我有以下对象字面值:

{ 
  'key1': 
  { 
    id: 'rr323',
    d: undefined,
    x: 560,
    y: 150 
  },
  'key2': 
  { 
    id: 'rr231',
    d: undefined,
    x: 860,
    y: 90 
  } 
}

我想实现一个if语句,如下所示:

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

我尝试了以下方法:

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

但是当它应该返回false时,它总是返回true值.

Answer 1

使用hasOwnProperty电话

if (!obj.hasOwnProperty(key)) {

}

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