My Javascript map object maps each key to an array. I have an issue with updating the array.

I tried to use a javascript object only.

const temp = {"map":[1], "what":[1,2]};
temp["what"].push(3);
console.log(temp);

It works but I still want to know whether there is a way to update the map object.

My original code is like this:

const temp = new Map();
temp.set("what", [1]);
temp["what"].push(2);
console.log(temp);

expect: {"what"=>[1,2]}

actual result:

VM6258:1 Uncaught TypeError: Cannot read property 'push' of undefined at <anonymous>:1:12

My Javascript map object maps each key to an array. I have an issue with updating the array.

I tried to use a javascript object only.

const temp = {"map":[1], "what":[1,2]};
temp["what"].push(3);
console.log(temp);

It works but I still want to know whether there is a way to update the map object.

My original code is like this:

const temp = new Map();
temp.set("what", [1]);
temp["what"].push(2);
console.log(temp);

expect: {"what"=>[1,2]}

actual result:

VM6258:1 Uncaught TypeError: Cannot read property 'push' of undefined at <anonymous>:1:12

• javascript

1 Answer 1

You need to use get with Map, i.e.

temp.get("what").push(2)