(tl;dr) The title is getting a lot of flack but I think there are two good patterns highlighted: 1) Avoid creating functions in React render and 2) Learn about and use defaultProps.<p>1: Example of arrow functions + Class property initializer: <a href="http:&#x2F;&#x2F;babeljs.io&#x2F;blog&#x2F;2015&#x2F;06&#x2F;07&#x2F;react-on-es6-plus&#x2F;" rel="nofollow">http:&#x2F;&#x2F;babeljs.io&#x2F;blog&#x2F;2015&#x2F;06&#x2F;07&#x2F;react-on-es6-plus&#x2F;</a>  
2: Default Props: <a href="https:&#x2F;&#x2F;facebook.github.io&#x2F;react&#x2F;docs&#x2F;reusable-components.html#default-prop-values" rel="nofollow">https:&#x2F;&#x2F;facebook.github.io&#x2F;react&#x2F;docs&#x2F;reusable-components.ht...</a>