¿Cómo se llama a una flecha en Reactjs?

How do you call an arrow in Reactjs?

Learn more at the React docs. If you use arrow functions within render , each call to render will create new function objects. If you then pass these functions to child elements via props , optimizations based on PureComponent or shouldComponentUpdate will fail (as the arrow function props will change on every render).

The arrow function returns a new function every time. This causes React to think something has changed in our view, when in fact nothing has. Simply moving that function from inline to a method on our class we completely fix the issue.

If you don’t use ES6 yet, you may use the create-react-class module instead: var createReactClass = require(‘create-react-class’); var Greeting = createReactClass({ render: function() { return Hello, {this.props.name}; } }); The API of ES6 classes is similar to createReactClass() with a few exceptions.

In short, with arrow functions there are no binding of this . In regular functions the this keyword represented the object that called the function, which could be the window, the document, a button or whatever. With arrow functions, the this keyword always represents the object that defined the arrow function.

Example: Call a Function After Clicking a Button import React from ‘react’; function App() { function sayHello() { alert(‘Hello! ‘); } return ( <button onClick={sayHello}> Click me! ); } export default App; The simple App component above has one function called sayHello(), and a single button.

Passing an arrow function in render will cause React to create a new function each time the component renders. But you don’t need to worry because the impact on performance is very minuscule.

In function components, we have currently no other choice but to either pass the callback directly from the props to the child component or to create an inline arrow function. You may want the latter if you need to control the arguments passed to the original callback. You need to be aware of 2 things in this example:

With the release of ES6 arrow function syntax, you now can use both regular JavaScript function and arrow function syntax when creating components. I would say that using the arrow function for React components is the right choice for most use cases. Let’s consider the basics of both syntaxes first.

Another way to remove the need for bind is to pass an arrow function into the onClick prop: Passing an arrow function in render will cause React to create a new function each time the component renders. But you don’t need to worry because the impact on performance is very minuscule.