you cannot use await outside of an async function.
so unless this is the interior of an async function the value of userid is a pending promise

you should either have this code within a async function, although that function also will return a promise.

async function x(){
    const userId = await AsyncStorage.getItem('userId');
    console.warn(userId);
    console.warn("When userId is not set I get a value of null");
    if (userId === null) {
        console.warn("However this check for null is not working");
        navigation.navigate("UserLoginWeb");
    }
}

or you should do something like this:

AsyncStorage.getItem('userId').then((userId)=>{
    console.warn(userId);
    console.warn("When userId is not set I get a value of null");
    if (userId === null) {
        console.warn("However this check for null is not working");
        navigation.navigate("UserLoginWeb");
   }
});
console.log("hello");

an asynchronous function does not block the main code, the code coming after will continue to be executed at the same time as the asynchronous request.
for example the hello in the above code will be executed before/simultaneously with the userid request.
i hope this helps.

This is a common issue with AsyncStorage in React Native. The potential issues here could be:

• AsyncStorage always returns strings or null. Sometimes it might return the string “null” instead of actual null, which would make === null fail.

• The check should handle both cases:

  if (userId == null || userId === ‘null’)

• It’s important to wrap AsyncStorage operations in try-catch blocks since they can fail.

The code below is a proper way to handle this:

import React, { useEffect } from 'react';
import AsyncStorage from '@react-native-async-storage/async-storage';

const CheckUserAuth = ({ navigation }) => {
  useEffect(() => {
    const checkUserId = async () => {
      try {
        const userId = await AsyncStorage.getItem('userId');
        console.warn('userId value:', userId);
        
        // Correct way to check for null/undefined
        if (userId == null || userId === 'null') {
          console.warn('User is not logged in');
          navigation.navigate('UserLoginWeb');
        } else {
          console.warn('User is logged in with ID:', userId);
        }
      } catch (error) {
        console.error('Error reading userId from AsyncStorage:', error);
        navigation.navigate('UserLoginWeb');
      }
    };

    checkUserId();
  }, [navigation]);

  return null; // Or your loading component
};

export default CheckUserAuth;

The above code uses proper error handling, handles both null and “null” cases, and wrapped in useEffect to properly handle the async operation. It also includes proper TypeScript/Flow-friendly type checking.

Make sure you’re awaiting the check in a proper async context. If the code is directly in your component body rather than in a useEffect or async function, it won’t work correctly. I hope this helps.