amirho/react.dev
1
0
Fork 0
mirror of https://github.com/reactjs/react.dev.git synced 2026-02-25 23:05:23 +00:00
Code Issues Packages Projects Releases Wiki Activity

Update handling-events.md (#8057)

Browse Source
This commit is contained in:
Alireza Mostafizi
2016-10-23 05:44:29 -07:00
committed by Dan Abramov
parent 3af93d6c2e
commit 25a1e5acae
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
docs/handling-events.md
View File

@@ -91,7 +91,7 @@ ReactDOM.render(
[Try it on CodePen.](http://codepen.io/gaearon/pen/xEmzGg?editors=0010)
You have to be careful about the meaning of `this` in JSX callbacks. In JavaScript, class methods are not [bound](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind) by default. If you forget to bind `this.toggle` and pass it to `onClick`, `this` will be `undefined` when the function is actually called.
You have to be careful about the meaning of `this` in JSX callbacks. In JavaScript, class methods are not [bound](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind) by default. If you forget to bind `this.handleClick` and pass it to `onClick`, `this` will be `undefined` when the function is actually called.
This is not React-specific behavior; it is a part of [how functions work in JavaScript](https://www.smashingmagazine.com/2014/01/understanding-javascript-function-prototype-bind/). Generally, if you refer to a method without `()` after it, such as `onClick={this.handleClick}`, you should bind that method.