React – expressions must have one parent element?
Put them in an array (assign the keys also): With latest React version, you can try React.Fragment also, like this:
reactjs
React-Redux: Actions must be plain objects. Use custom middleware for async actions
You have to dispatch after the async request ends. This would work:
React Uncaught Error: Target container is not a DOM element [duplicate]
The way you have it it runs before you even have DOM. You should include it in the bottom like so:
What does this “react-scripts eject” command do?
create-react-app encapsulates all of the npm modules it is using internally, so that your package.json will be very clean and simple without you having to worry about it. However, if you want to start doing more complex things and installing modules that may interact with modules create-react-app is using under the hood, those new modules … 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
How to include bootstrap css and js in reactjs app?
If you are new to React and using create-react-app cli setup, run the npm command below to include the latest version of bootstrap. or Then add the following import statement to index.js file. (https://getbootstrap.com/docs/4.4/getting-started/webpack/#importing-compiled-css) or don’t forget to use className as attribute on target elements (react uses className as attribute instead of class).
ReactJS: setTimeout() not working?
Do Otherwise, you are passing the result of setState to setTimeout. You can also use ES6 arrow functions to avoid the use of this keyword:
Uncaught TypeError: Cannot read property ‘props’ of null
Since you are not using React.createClass in class methods this doesn’t refers to the component instance, so you should bind it manually. There are several ways: 1. Manually bind this in class constructor 2. Use ES7 Property initializers with arrow function 3. Bind this at call-site In render() method:
Setting onSubmit in React.js
In your doSomething() function, pass in the event e and use e.preventDefault().