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Discussion on: React Quick Tip: Use Class Properties and Arrow Functions to Avoid Binding `this` to Methods

davejs profile image
David Leger Author

Nice! Yes, that certainly works depending on the the use case. This approach works because render() is bound to this of the class by React.

Keep in mind however that you'll have a (rather small) performance hit because the onClick function is being initialized every time render is invoked since that is where it is being defined.

enriquemorenotent profile image
Enrique Moreno Tent

Well, I am not sure if such a thing can be called a "performance hit" since we are talking basically of 1 line of code, and there are plenty of those that run every time the render starts. The complexity of the operation is not even exponential but linear. I don't think that there is any performance concern to worry about in this case.

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tokland profile image
Arnau Sanchez • Edited on

Enrique, I am afraid there really is a performance hit. Not because you are creating an arrow function on the fly - as you say, that's mostly irrelevant-, but because a new function will be passed as a prop and the component will re-render (needlessly).

If this happens with a button, that's not a problem, but more complex components will noticeably slow down your apps. This is a known caveat, you'll find many references in the web (for example: