I made a break from my react native project for about 3 weeks and now I came back and wanted to work on it, unfortunaly the app doesnt even render the first screen components. I already figured out what the problem is, Im just totaly confused what is going on:
var chatkeys = [];
var partnerkeys = [];
var contactsDATA = [];
await firebase.database().
ref(`users/${PersonalId}/chats`).
once('value').
then(snapshot =>{
for (i in snapshot.val()){//pulling all chatcodes out of database and pushing into chatkeys
chatkeys.push(snapshot.val()[i]);
};
});
The problem is located in the for-loop. Here is the error Im receiving:
[Unhandled promise rejection: ReferenceError: Can't find variable: i]
- node_modules\react-native\node_modules\promise\setimmediate\core.js:37:13 in tryCallOne
- node_modules\react-native\node_modules\promise\setimmediate\core.js:123:24 in setImmediate$argument_0
- node_modules\react-native\Libraries\Core\Timers\JSTimers.js:130:14 in _callTimer
- node_modules\react-native\Libraries\Core\Timers\JSTimers.js:181:14 in _callImmediatesPass
- node_modules\react-native\Libraries\Core\Timers\JSTimers.js:441:30 in callImmediates
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:387:6 in __callImmediates
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:135:6 in __guard$argument_0
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:364:10 in __guard
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:134:4 in flushedQueue
- [native code]:null in flushedQueue
- [native code]:null in callFunctionReturnFlushedQueue
How can JS not find the variable "i"? I never told JS to search for "i" - it's just supposed to be a counter to loop through the whole snapshot.val() array. What is going on here?
The error states that i
is not defined. reading your code, I can see that i
inside your for loop declaration may be missing the let i
variable.
Have you tried for (let i in snapshot.val()){
i
is not declared in the scope. Try
for (let i in snapshot.val()){//pulling all chatcodes out of database and pushing into chatkeys
chatkeys.push(snapshot.val()[i]);
};
OR
let i;
for (i in snapshot.val()){//pulling all chatcodes out of database and pushing into chatkeys
chatkeys.push(snapshot.val()[i]);
};
I made a break from my react native project for about 3 weeks and now I came back and wanted to work on it, unfortunaly the app doesnt even render the first screen components. I already figured out what the problem is, Im just totaly confused what is going on:
var chatkeys = [];
var partnerkeys = [];
var contactsDATA = [];
await firebase.database().
ref(`users/${PersonalId}/chats`).
once('value').
then(snapshot =>{
for (i in snapshot.val()){//pulling all chatcodes out of database and pushing into chatkeys
chatkeys.push(snapshot.val()[i]);
};
});
The problem is located in the for-loop. Here is the error Im receiving:
[Unhandled promise rejection: ReferenceError: Can't find variable: i]
- node_modules\react-native\node_modules\promise\setimmediate\core.js:37:13 in tryCallOne
- node_modules\react-native\node_modules\promise\setimmediate\core.js:123:24 in setImmediate$argument_0
- node_modules\react-native\Libraries\Core\Timers\JSTimers.js:130:14 in _callTimer
- node_modules\react-native\Libraries\Core\Timers\JSTimers.js:181:14 in _callImmediatesPass
- node_modules\react-native\Libraries\Core\Timers\JSTimers.js:441:30 in callImmediates
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:387:6 in __callImmediates
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:135:6 in __guard$argument_0
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:364:10 in __guard
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:134:4 in flushedQueue
- [native code]:null in flushedQueue
- [native code]:null in callFunctionReturnFlushedQueue
How can JS not find the variable "i"? I never told JS to search for "i" - it's just supposed to be a counter to loop through the whole snapshot.val() array. What is going on here?
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.