Question

99

Javascript - set all keys of a Map object to a value

rated 0 times [ 106] [ 7] / answers: 1 / hits: 5483 / 5 Years ago, sat, april 27, 2019, 12:00:00

I have this code here:

const myMap = new Map()



myMap.set(banana, true)

myMap.set(apple, true)



Object.keys(myMap).forEach(key => {myMap.set(key, false)})



console.log(myMap.get(banana)) // returns true should return false

console.log(myMap.get(apple)) // returns true should return false

I want to set all the values of this Map to false, but it doesn't work at all.

I've tried something like this:

Object.keys(myMap).forEach(key => myMap[key] = false)

but this doesn't work either.

Is there a way to fill all keys of a Map to a specific value?

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daja

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answered 5 Years ago naya · Accepted Answer

You have to specifically call Map.set in order to set a value in a Map. myMap[key] = value will only work for plain objects. You should also use myMap.keys() to get an iterator of the map's keys:

const myMap = new Map();



myMap.set(banana, true);

myMap.set(apple, true);



[...myMap.keys()].forEach((key) => {

  myMap.set(key, false);

});



console.log(myMap.get(banana));

console.log(myMap.get(apple));