Javascript key exists
snippet in javascript

Javascript key exists

user7901

var person={"name":"Billy","age":20}
person.hasOwnProperty("name"); // true
person.hasOwnProperty("sex"); // false

javascript hashtable contains key

user3554

if (obj.hasOwnProperty("key1")) {
  ...
}

check if a key exists in an object javascript

user833

"key" in obj // true, regardless of the actual value

js check if object key exists

user9194

var obj = { key: undefined };
obj["key"] !== undefined // false, but the key exists!