JIYIK CN >

When we use the useState hook to declare an empty state array but do not type the array, we get the error Type is not assignable to type never. To fix the error, use generics to type the state array, such as const [arr, setArr] = useStatestr...

To prevent a page refresh when a form is submitted in React, use the preventDefault() method on the event object, for example event.preventDefault() . The preventDefault() method prevents the browser from taking the default action, which in the case o...

The Nothing was returned from render React error occurs when we forget to explicitly return a value from a function or class component. To fix the error, explicitly return JSX from our component, use implicit returns with arrow functions, or...

To create N identical components/elements in React: Use Array.from() method to generate an array of N elements. Replace each element in the array with the actual component. Render the array of elements. function Header () { return h2 Hello world / h2 ...

React.jsAttempted import error X is not exported from appears when we try to import a named import that does not exist in the specified file. To resolve the error, make sure the module has named exports and that we are not mixing named exports with de...

To concatenate JSX elements into an array in React: Initialize an empty array. Use the push() method to push JSX elements into the array. Set the key attribute on the outermost JSX element to a unique value. export default function App () { const fru...

Use the useSearchParams hook to programmatically update query parameters in React Router, for example, setSearchParams({query: myValue}) . The useSearchParams hook is used to read and modify the query string in the URL of the current location. import ...

To fix the React.js warning Invalid DOM property for . Did you mean tmlFor . Use the htmlFor attribute because for is a reserved word in JavaScript. Here is an example of how the warning is generated. export default function App () { // ⛔️ Warning...

React.js error X is not defined react/jsx-no-undef occurs when we forget to import a function, class, or variable before using it in our code. To fix this error, make sure to import the value before using it in our code, e.g. import {myFunc} from my-...

To set background color using inline styles in React: Set the style attribute on the element. Set the backgroundColor attribute to a specific color. import {useState} from react ; export default function App () { const [isActive, setIsActive] =...

To detect when the user presses the backspace key in React.js: Add the onKeyDown prop to the input element. Every time the user presses a key in the input field, check if the key pressed was the backspace key. Call a function or run some logic if it i...

Check if the input value is a valid number in React: Check if the input value is not an empty string or contains only spaces. Pass the value to the isNaN() function. If isNaN returns false , then the value is a valid number. import {useState} from rea...

There are multiple reasons why the Component cannot be used as a JSX component error appears: Returning an array of JSX elements instead of a single element. Returning any value other than a JSX element or null from a component. Having an outdated ver...

To create an input field that contains only allowed numbers using React.js: Set the input field's type to text. Add an onChange event handler that removes all non-numeric values. Save the input value in a state variable. import {useSt...

Passing functions as props in React TypeScript: Define the type of the function property in the component's interface. Define the function in the parent component. Pass the function as a prop to the child component. interface ButtonProps { sum : ( a: ...