App.js TestBox.js Codesandbox of the example above Main Question Assuming that I didn’t read the source code in TestBox.js, how to find out that TestBox.js provided 2 parameters (data1 & data2) to my functions? More Context I frequently have this problem when I use third party libararies, as an exam…
Tag: reactjs
Why does this short circuit evaluation return undefined if first value is false?
I have an example similar to this where the first expression evaluates to false and the second is undefined but the overall expression returns undefined into valueResult, shouldn’t the first false value terminate the check and return false? I have added console log statements and a debugger and this is …
How do I use a fetch get response more than once?
I want to set both of these values in the state to be used later as variables. But it gives the error: How do I fix this? Answer Try this: The last two .then statements need to be combined. By calling .then twice, you’re sending the result of setDollarValue() (a void function) to the next .then, which i…
what is difference between useCallback and useMemo in react hooks?
can you tell me. what is difference between useCallback() and useMemo() in react hooks and when is the function used or what are the examples? Answer useMemo: A hook used to memorize a value, when certain values of the dependency array change. Instead, useCallback memorizes a function, a callback, so when the…
React img onError not firing
I am trying to use a third-party API for getting YouTube thumbnails with higher resolution, which sometimes fails with code 404. If I fail to fetch the image, I would like to replace the src with the default YouTube thumbnail retrieved using its own API (I have the url stored in a json). When I tried to imple…
How to pass values to parent from child of child?
I have a parent component, with a child, which also has a child. When a value is defined in child two, I am passing that value using a callback to child one, but I also want to pass the same value back to the parent. Unfortunately using a similar callback seems two throw the error that the identifier has alre…
replacing createStore with configureStore
I updated my packages and VScode told me that createStore was depreciated. So I went about replacing it My store file, I have included the original line as a comment at the bottom Using redux App component With configureStore() the console is giving me a warning about putting non-serizible objects in state. T…
could not render component in react
When I use history.push () method, from signup to log in, goes to a particular API/URLenter code here but does not render the login component. Answer Do not create new history. You can use useHistory that exported from react-router-dom instead and get the current history. It would be something like this:
Why is this function behaving differently on calling first time and second time in React js?
I am trying to implement a turn by turn navigation with mapbox gl js in react,I am trying to make the marker positon update smooth instead of it being teleported.So to perform the animation I am trying to call a function recursively but for some reason the same function behaves differently when called second …
react-window rows call useState
I’m trying to render a stateful component inside react-window rows (using FixedSizeList), but their state (useState) is not maintained when they get re-rendered so it resets every time I scroll back to them. This makes sense because they’re getting unmounted, but is there a way prevent re-renderin…