Question: Using Admin-sdk, Is there a way to delete a particular provider from a user record in firebase?

For eg:
Assume a given user has the following providers linked to his account

1. password
2. google.com
3. facebook.com

Say, I would like to revoke the user's ability to login via facebook to his account. Can this be done using admin sdk.

I could only find an api to unlink a provider (which is client side api. This will require the firebase-issued-idToken of the user).

Answer: 
You need to declare the variable first, and then assign it values on separate lines.

```
pragma solidity ^0.8;

contract MyContract {
    mapping(address => bool) public myMap;

    constructor() {
        myMap[address(0x123)] = true;
        myMap[address(0x456)] = false;
        myMap[address(0x789)] = true;
    }
}

```
Unfortunately, you can't. See the Solidity documentation for details on the reasons why. Your only option is to iterate through the keys.

If you don't know your set of keys ahead of time, you'll have to keep the keys in a separate array inside your contract.