The logic behind declarations behind mappings

[gmluqa]

Hello,

I am 2hr40 mins deep in the Javascript Edition course so far, my doubt is related to the following lines:
mapping(string => uint256) public nameToFavoriteNumber;
and

function addPerson(string memory _name, uint256 _favoriteNumber) public {

        People memory newPerson = People({favoriteNumber: _favoriteNumber, name: _name});   

        people.push(newPerson);

        nameToFavoriteNumber [_name] = _favoriteNumber;

    }

Specifically, nameToFavoriteNumber [_name] = _favoriteNumber;. Why exactly is _name closed in square brackets? Is there any reason _favoriteNumber isn't?

Thank you.

[vivart]

mapping data type stores data in the form of key value pair.
mapping(string => uint256) public nameToFavoriteNumber in this case we are going to store key of type string and value of type uint256.
We store key/value to map like
mapVariable[key] = value
in our case nameToFavoriteNumber [_name] = _favoriteNumber;

[gmluqa]

Aha, so the [key] is always in square brackets and the value is left as is, thank you very much.

[PatrickAlphaC]

Great answer @vivart