js key exsists code example
Example 1: js check if object key exists
var obj = { key: undefined };
obj["key"] !== undefined // false, but the key exists!Example 2: js key in dict
"key" in obj // true, regardless of the actual valuevar obj = { key: undefined };
obj["key"] !== undefined // false, but the key exists!"key" in obj // true, regardless of the actual value