Of course, Object.keys() is the best way to get an Object's keys. If it's not available in your environment, it can be trivially shimmed using code such as in your example (except you'd need to take into …

Object.keys () is a javascript method which return an array of keys when iterating over objects.

Jun 18, 2010 · I have a JavaScript object like var obj = { key1: 'value1', key2: 'value2', key3: 'value3', key4: 'value4' } How can I get the length and list of keys in this object?

Apr 22, 2021 · I'd avoid modifying Object.prototype - as another commenter noted below, this can easily break scripts which aren't careful about checking hasOwnProperty (). Instead, use the less OO …

Jan 17, 2013 · Javascript Maps keep keys in insertion order, meaning you can iterate over them without having to check the hasOwnProperty, which was always really a hack. Iterate over a map:

Object.keys () returns an array whose elements are strings corresponding to the enumerable properties found directly upon object. The ordering of the properties is the same as that given by looping over …

The in operator matches all object keys, including those in the object's prototype chain. Use myObj.hasOwnProperty('key') to check an object's own keys and will only return true if key is …

I have a quite simple JavaScript object, which I use as an associative array. Is there a simple function allowing me to get the key for a value, or do I have to iterate the object and find it out

Nov 29, 2011 · A JSON object and a Javascript object are different things, and you might want to iterate through the properties of a JSON object using the solutions proposed above, and then be surprised.

Mar 26, 2009 · In javascript, every object has a bunch of built-in key-value pairs that have meta-information. When you loop through all the key-value pairs for an object you're looping through them …