Jul 16, 2020 · let updatedList = state.todos.map(item => { if (item.id == id){ return {...item, done: !item.done}; //gets everything that was already in item, and updates "done" } return item; // else return unmodified item }); setState({todos: updatedList}); // set state to new object with updated list }

Dec 13, 2024 · This article explores how to use JavaScript to update the browser's state dynamically and create seamless navigation experiences.

Jan 14, 2018 · I am trying to update state with API. I tried to update API state with using setouttime, in render(), there is if statement which if timepassed is true, this.get_bus will be called to update state.

Mar 27, 2025 · The replaceState() method of the History interface modifies the current history entry, replacing it with the state object and URL passed in the method parameters. This method is particularly useful when you want to update the state object or URL of the current history entry in response to some user action.

I want to update the state when the user changes any of the values, but I'm having a hard time to target the correct object: handleChange: function (e) { item = this.state.items[1]; item.name = 'newName'; items[1] = item; this.setState({items: items});

Instead of mutating an array, create a new version of it, and update the state to it. You can use the [...arr, newItem] array spread syntax to create arrays with new items. You can use filter() and map() to create new arrays with filtered or transformed items.

State can hold any kind of JavaScript value, including objects. But you shouldn’t change objects that you hold in the React state directly. Instead, when you want to update an object, you need to create a new one (or make a copy of an existing one), and then set the state to use that copy.

Dec 19, 2019 · The useState hook returns the state value and a function for updating that state: import React from 'react'; function BooksList () { const [books, updateBooks] = React.useState([]); } The above example shows how to use the useState hook.

Sep 9, 2019 · We use a third party library (over which there is limited control) that takes a callback as argument to a function. What is the correct way to provide that callback with the latest state? In class components, this would be done through the use of this.

Dec 11, 2023 · This article will guide you through the principles of state management in plain JavaScript, showcasing how you can effectively manage, update, and share state across your application without ...