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I'm looking for a one-liner way of checking if a key exists and if it doesn't create it.
var myObject = {}; //Anyway to do the following in a simpler fashion? if (!('myKey' in myObject)) { myObject['myKey'] = {}; } 
980
Using the indexOf() Method JavaScript's indexOf() method will return the index of the first instance of an element in the array. If the element does not exist then, -1 is returned.
Use the in operator to check if a key exists in an object, e.g. "key" in myObject . The in operator will return true if the key is present in the object, otherwise false is returned. Copied! The syntax used with the in operator is: string in object .
There are mainly two methods to check the existence of a key in JavaScript Object. The first one is using “in operator” and the second one is using “hasOwnProperty() method”. Method 1: Using 'in' operator: The in operator returns a boolean value if the specified property is in the object.
Using has_key() method returns true if a given key is available in the dictionary, otherwise, it returns a false. With the Inbuilt method has_key(), use the if statement to check if the key is present in the dictionary or not.
Short circuit evaluation:
!('myKey' in myObject) && (myObject.myKey = {}) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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