Aug 24, 2019 · 6 It's Array.prototype.map actually, it's defined for arrays, so use Array.from to convert the keys to an array and then use map:

Feb 4, 2019 · I have a Map() object that I need to iterate, so I can get the day of the week and a selected hour. The code below doesn't work, because Object.keys(newFieldReservationPrice).forEach is …

Jun 27, 2015 · See my answer, Array.from takes a map function as a param, you don't need create a temporary array just to map over it and discard it.

May 10, 2017 · Say we have a Map: let m = new Map();, using m.values() returns a map iterator. But I can't use forEach() or map() on that iterator and implementing a while loop on that iterator seems like …

Jul 14, 2016 · The second argument of Array.map() is a object which will be the this value for the callback function. Keep in mind that you have to use the regular function keyword in order to declare …

I just discovered this feature: Map: Map objects are simple key/value maps. That confused me. Regular JavaScript objects are dictionaries, so how is a Map different from a dictionary? Conceptually,

Feb 11, 2013 · 1) map has no meaning without callback 2) if callback isn't function, yours map implementation just runs meaningless for-loop. Also, Object.prototype.hasOwnProperty.call( obj, key …

Nov 6, 2017 · There isn't any direct method for picking out information in this direction, so if all you have is the map you need to loop through the set as suggested by others. If the map/array/other is large …

Apr 15, 2016 · 398 Yes, the Map constructor takes an array of key-value pairs. Object.entries is a new Object static method available in ES2017 (19.1.2.5).

Mar 28, 2019 · There is quite some topics posted about how async/await behaves in javascript map function, but still, detail explanation in bellow two examples would be nice: const resultsPromises = …