react-native
React Native version mismatch
This is what I’ve done with it: Close all terminals and run build again. You may forget to close nodejs terminal from another project, and they happen to have installed different react version. So the code fetches from nodejs server conflicts with the native one.
TypeError: Invalid attempt to spread non-iterable instance
This is because it is a runtime error, not a “compile time” error. Is there a line number associated with the error? Based on the question being about the spread operator I’ll assume it’s this line: newArticlesData=[…prevData,…response.data]. I assume your prevData is iterable, but is your response data? Try newArticlesData=[…prevData, response.data]? Here’s an example of invalid spread operator use:
Is using async componentDidMount() good?
Let’s start by pointing out the differences and determining how it could cause troubles. Here is the code of async and “sync” componentDidMount() life-cycle method: By looking at the code, I can point out the following differences: The async keywords: In typescript, this is merely a code marker. It does 2 things: Force the return type to be Promise<void> instead of void. … Read more
When to use useImperativeHandle, useLayoutEffect, and useDebugValue
Allow me to preface this answer by stating that all of these hooks are very rarely used. 99% of the time, you won’t need these. They are only meant to cover some rare corner-case scenarios. useImperativeHandle Usually when you use useRef you are given the instance value of the component the ref is attached to. This allows you to … Read more
why do I get react-native command not found error on windows pc?
in the current directory do you will get the following if it shows command not found the n you have not installed react native in the directory. Do a npm init in new folder and try installing a new react native project there by doing npm install -g react-native-cli Follow the steps to add path variable react-native. … Read more
Timers in React Native (this.setTimeout)
Settimeout and setInterval still work in react-native. BUT you have to use it in the right way: Here is one of many ways to implement a timeout in React that I’m usually used: With this approach you don’t have to worry about memory leak anymore. Just simple and straight forward. There is an excellent article … Read more
React Navigation back() and goBack() not working
The key property for goBack() is a dynamically created string, created by react-navigation whenever it navigates to a new route. for example: It is stored in this.props.navigation.state.key. So if you want to go from EditPage to Cover, what you have to do is to pass the key of EditCover down to EditPage, and then call goBack() with the key. Why not key of Cover but EditCover? Because react-navigation only provides the method goBack(key), it’s go … Read more
react-native: command not found
After adding right path to the PATH variable issue is resolved. Below are the steps to find the right path. from above output you can clearly see the path: /usr/local/Cellar/node/6.1.0/libexec/npm/bin/react-native if you getting xcrun: error: unable to find utility “simctl” at this stage you can reslove using below steps XCode -> Preferences -> Locations -> Command Line Tools … Read more
What is prevState in ReactJS? [duplicate]
prevState is a name that you have given to the argument passed to setState callback function. What it holds is the value of state before the setState was triggered by React; Since setState does batching, its sometimes important to know what the previous state was when you want to update the new state based on the previous state value. So … Read more